union at the central line of the body during the fœtid existence of an animal, and some malformations cannot be accounted for in any way. According to the popular belief, fright and similar effects on the mind may cause malformations in the fœtus of a pregnant female. Some scientists attribute some of such phenomena to reversion, pure and simple; others to influences the nature of which is not clearly understood, and the name of infection or impregnation has been given to it. Instances of this kind are too numerous to deny their occurrence altogether.

Of a different kind are the following phenomena :-A brown mare of a race where this colour was prevalent, having been covered by a brown entire of the same breed, gave birth to a chestnut foal. It was ascertained that the entire had only lately covered a chestnut mare, the only one of that colour in the whole district. After the removal altogether of the chestnut mare from the district, the brown mare had several brown foals in succession by the same entire. This instance has been quoted as a case where a strong mental impression on the male exercised an indirect effect on the female. It is quite as possible, however, that we have here a case of reversion pure and simple. Some of the ancestors of either the male or female may have been of chestnut colour.

It is also maintained that such and similar effects on the female may be lasting. This is said to have been observed in countries where mules are bred and used in preference to horses. Dr. Miles's evidence on this head is abundant; it fills about fifteen pages of his work, but I shall here be able to give a few instances only. Mention is made in the "Philosophical Transactions" of the year 1821 of a chestnut mare, seven-eighths Arabian, belonging to the Earl of Morton, that was covered by a quagga; the hybrid produce resembled the sire in colour and in many peculiarities of form. In 1817, 1818, and 1821 the same mare was covered by a very fine Arabian horse, and produced successively three foals, and although she had not seen the quagga since 1816 they all bore his curious and equivocal markings.

It is stated, on the authority of Mr. William Goodwin, veterinary surgeon to Her Majesty, that several of the mares in the Royal stud at Hampton Court had foals in one year which were by Acteon, but which presented exactly the marks of the horse Colonel--a white hind fetlock, for instance, and a white mark or stripe on the face; and Actæon was perfectly free from white. The mares had all bred from Colonel the previous year.

Alexander Morrison, Esq., of Bognie, United States, had a fine Clydesdale mare which, in 1843, was served by a Spanish ass and produced a mule. She afterwards had a colt by a horse, which colt bore a very marked likeness to a mule. Seen at a distance, everyone set it down at once as a mule. The ears are 9 inches long, the girth not quite 6 feet, and he stands above 16 hands high. The hoofs are so long and narrow that there is a difficulty in shoeing them, and the tail is thin and scanty. He is a beast of indominable energy and durability, and is highly prized by his owner.

Rueff says:-"As a horse-fancier I have taken special notice of such facts as they have come under my notice in my journeys through Piedmont, Upper Italy, and the South of France. Mares that have been covered by donkeys frequently produce, even when covered by a horse, offspring that so strongly resemble mules that they may easily be taken for such. The celebrated painter, Professor Wagner, noticed the same whilst travelling through Spain."

A German sheep-breeder, Mr. Rimpau, had 15 merino ewes covered by a Southdown ram; the offspring showed the grey heads and extremities of the Southdown ram. Later on the same ewes were covered by a Rambouillet ram; the result was that 12 out of 15 of those ewes produced lambs which were marked in a similar manner as the half-bred Southdowns-their mothers. Scientists have tried to explain these cases, as I said before, firstly, by a strong mental effect which the male exercises on the female; secondly, by a possible migration of the spermatozoa or seed animalcula into the ovary; or, thirdly, by the intermixture of the blood of the foetus with that of the mother during gestation. With regard to the first explanation it may be said to be possible;

as to the second, it may be argued that such migration of spermatozoa from the vagina into the ovary has never been traced nor proved, and if it had taken place the effects would have been that more ovules would have come to maturity at the same time; the third explanation can scarcely be accepted, because according to some physiologists there is no true circulation between foetus and mother, as had been supposed to exist, and that the foetus grows by osmosis.

Dr. Carpenter says:-" Some of these cases appear referable to the strong mental impression left by the first male parent upon the female; but there are others which seem to render it more likely that the blood of the female has imbibed from the foetus through the placental circulation some of the attributes which the latter has derived from its male parent, and that the female may communicate these with those proper to herself to the subsequent offspring of a different male parentage." Professor Agassiz seems to be inclined to hold the secondly mentioned explanation. He has shown that turtles begin to copulate at the age of seven years, but do not lay until they are eleven years old; they copulate twice each year for four years before the eggs are fully matured. Upon opening large numbers of young freshwater turtle of the species Chrysemys, it was ascertained that up to their seventh year the ovary contained only eggs of very small size, not distinguishable into sets; but with every succeeding year there appears in that organ a larger and larger set of eggs, each set made up of the usual average number of eggs which this species lays, so that specimens eleven years old for the first time contain mature eggs ready to be laid in the spring.

From the observations made by Agassiz it appears that the first copulation coincides with a new development of the eggs, in consequence of which a number of them, equal to that which the species lays, acquire a larger size and go on growing for four successive years before they are laid; while a new set is started every year at the period of copulation in the spring, enabling this species to lay annually from 5 to 7 eggs after it has reached its eleventh year.

After a careful examination of all the known facts bearing upon this interesting subject, Agassiz became satisfied that the first copulation only determines the further growth of a certain number of eggs, which require a series of successive fecundations to undergo their final development, and that in turtles a repetition of the act, twice every year for four successive years, is necessary to determine the final development of a new individual, which may be accomplished in other animals by a single copulation.

In a subsequent lecture, in speaking of the influence of previous impregnation upon offspring at a later period, Agassiz says:-" It therefore shows what I have satisfied myself to be the truth among other animals by numerous experiments: that the act of fecundation is not an act which is limited in its effects, but that it is an act which affects the whole system, the sexual system especially, and in the sexual system the ovary to be impregnated hereafter is so modified by the first act that later impregnations do not efface that first impression.”

Darwin, in his “Animals and Plants under Domestication," cites a number of instances in the vegetable kingdom to show the direct action of the male element on the mother form, and he comes to the conclusion that "the male element not only affects, in accordance with its proper function, the germ, but the surrounding tissues of the mother plant." Further on, Darwin remarks: "The analogy from the direct action of foreign pollen on the ovarium and seedcoats of the mother plant strongly supports the belief that the male element acts directly on the reproductive organs of the female, wonderful as is this action, and not through the intervention of the crossed embryo."

Here we have a doctrine of great importance before us. For it is evident to every practical breeder that we might economise the services of valuable sires if we could place implicit reliance upon its holding good in every species, and under all circumstances. In the meantime, these facts may serve as a caution to be careful in never allowing a female to be mated with an inferior male, especially at the first time.

Reversion generally means the reappearance of the bad qualities of some inferior ancestors, and we say that animals are degenerating if the reversion to inferior ancestors has been so frequent as to threaten a total loss of the good qualities we desire to cultivate and to fix. I have known several flocks in Queensland where the traces of the good rams that had been used at one time had become completely obliterated, so to speak. Bad qualities had sprung up again and increased. Darwin explains the nature of this reversion or throwing back by the following illustration:

"Some facts in regard to the colouring of pigeons well deserve consideration. The rock-pigeon is of a slaty blue, and has a white croup. The tail has a terminal dark bar, with the bases of the outer feathers externally edged with white, the wings have two black bars. Some semi-domestic breeds, and some apparently truly wild breeds, have, besides the two black bars, the wings chequered with black. These several marks do not occur together in any other species of the whole family. Now, in every one of the domestic breeds, taking thoroughly wellbred birds, all the above marks, even to the white edging of the outer tail feathers, sometimes occur perfectly developed; moreover, when birds belonging to two or more distinct breeds are crossed, none of which are blue or have any of the above specified marks, the mongrel offspring are very apt suddenly to acquire these characters. To give one instance out of several which I have observed :-I crossed some white fantails, that breed very true, with some black barbs, and it so happens that the blue varieties of the barbs are so rare that I never heard of an instance in England, and the mongrels were black, brown, and mottled. I also crossed a barb with a spot, which is a white bird with a red tail, and red spot on the forehead, and which notoriously breeds very true; the mongrels were dusky and mottled. I then crossed one of the mongrel barb fantails with a mongrel barb spot, and they produced a bird of as beautiful a blue colour, with a white croup, double black wing bar, and barred and white-edged tail feathers, as any wild rock-pigeon. We can understand these facts on the wellknown principle of reversion to ancestral characters, confined, as far as I have seen, to colour alone, if all domestic breeds have descended from the rock-pigeon." It is thus evident that some animals possess a higher degree of transmitting power than others; but wherever the possibility of tracing back to the qualities of ancestors is at hand, we shall probably find that the ancestors of such animals were in possession of those qualities in a high degree of perfection and constancy of blood.

Such power is called "prepotency." It means a higher degree of transferring power than usual. Some writers have maintained that "prepotency is a peculiarity apart from that power of transferring, which is the result of pure blood and high breeding; that it is the result, rather, of a peculiar organisation of the individual; and that it is, so to speak, a gift of nature, not to be credited to descent from a series of superior ancestors.”

However, there are no records in the history of breeding from which we are justified in presuming that such an individual prepotency really exists. In order to prove it, we must show authenticated instances that mongrels (ie., animals without claim to good blood) ever did become, owing to such individual prepotency, the progenitors of a permanently superior race of animals. Such proof has never been given. Some animals certainly show a superior power than others of transferring their own good qualities, and occasionally in a higher degree of perfection. Such facts, however, can generally be explained as the results of a greater accumulation of good qualities in the blood of the animals in question, as derived from good ancestors.

Settegast enumerates a number of instances where animals have produced exceptionally good offspring, in some cases much better even than they were themselves. The Shorthorn bull Hubback is credited by Settegast with that individual prepotency. It is well known, however, that Hubback was descended from the Teeswater cattle, a race then already famous for those very points which in a higher degree were the characteristics of Hubback. A few chance foals of very

superior qualities led to inquiries about the possible progenitor of them, and the circumstances pointed to a very old horse of unknown history. Here was (according to Settegast) a case of true prepotency. Closer examination of this equine Nestor revealed the well-known brand of a famous stud.

In such cases it has been invariably proved that these "prepotentiated" animals have sprung from bona fide blood ancestors.

It is easily understood how any herd or flock, that has been inbred for some time, will eventually reach a point where further improvements are either very slow or impossible. The system of inbreeding within a certain limit of qualities, and under the influence of the same food, climatic and other conditions, must have the effect of eventually precluding further variations, let them be ever so slight. Every improvement is to some extent a variation. Animals may have reached that standard of perfection, beyond which it is, under existing circumstances, impossible to bring them. If we now introduce a new sire of almost the same blood, but bred in an entirely different locality and under difierent conditions, the tendency to variation (though within certain limits) is introduced anew; and a fresh impulse is thus given to the formation of new characters. Of this the history of breeding gives numerous instances. It is frequently after the introduction of fresh blood of similar or the same descent that these prepotentiated prodigies turn up. Amongst the Australian sheep the appearance of some of them may be attributed to the Vermont blood (President?); others to Staiger, Gadegast rams, &c.

Many breeders hold that the sire tends to transmit the average qualities of his ancestors. This is true up to a few generations backwards. The reappearance of less desirable qualities, as they existed in earlier generations, would be a case of throwing back.

The closer the animals to be mated are related to each other, the stronger will be their influence in transmitting their qualities to their offspring. If father and mother have an equal degree of transmitting power, they will have an equal influence on their offspring. The more equal both parents are, and the more similar their parents have been, the more perfect will their qualities be transferred to their progeny. The more unlike the parents are, and neither of them sprung from a constant breed, the more reversions will appear in their offspring for many generations to come. Darwin says:-"A breed intermediate between two very distinct breeds could not be got without extreme care and longcontinued selection; nor can I find a single case on record of a permanent race having been thus established." If animals, sprung from violent crosses, are coupled with each other, sure results can hardly be expected; a deterioration generally ensues. Parents of different size and carcass will seldom produce an offspring of good proportions, also the products of coarse and fine-woolled sheep show always great unevenness throughout the fleece. If there are in a breed animals which answer the purposes of the breeder pretty nearly, favourable results of breeding, so far as the development and the increase of desirable qualities go, will better be accomplished by the inbreeding of such animals than by crossing them with others sprung from a different breed. The very existence of good animals proves that conditions favourable to the production of such animals are frequent, and exist à priori in the blood of this breed. The present qualities (good or bad) will, by inbreeding, be consolidated in course of time and be constantly transferred, while any admixture of other blood gives occasion to reversion on the part of the new blood. With reference to the French breed of Lacharmoise, the founder of it makes the following remark:-"Crosses have been tried for some time between French and English sheep, yet all our efforts and trials failed; nobody ever succeeded, as sometimes the English blood, sometimes the original French blood reappeared. I explained. to myself this unsatisfactory result through my not paying sufficient attention to the law of inheritance, following which animals transfer their qualities according to the comparative length of time during which their ancestors have possessed these qualities. The English sheep, however, particularly those of the Leicester

breed, are of modern origin only; consequently they possess less individual capability of transmission than those of the French race, whose origin could be traced back for several centuries."

Thus I thought it advisable to diminish the resisting tendency of our French sheep against the transfusion of English blood into their offspring. In order to obtain ewes of no resistance against the English blood, I chose such ewes which originated from four different races of sheep in France, mixed them amongst themselves, and received at last animals without any distinct character or type, and which should possess the slightest possible inheritance. In this way I received lambs (got by the English Leicesters) which possessed 50 per cent. of Leicester blood, and 124 per cent. of either of those four French races. The French blood had thus to give way to the power of inheritance on the part of the English blood. The influence of the English type is indeed so decided and powerful that all lambs I bred in this way are considered to be pure blood English, and they perfectly resemble each other. Everyone of them which shows a remarkable reversion to the French race is culled, in order to improve the consolidation of the new race. This, he says, "is the mystery of the

Lacharmoise breed."

Le Fevre mentions a similar instance of the difficulty of producing a valuable breed from animals that have a tendency to reversion. The origin of the Mauchamp breed dates from the December of the year 1828, when Mons. Graux, the founder of the flock, noticed a ram lamb that distinguished himself from all the others through his good carcass and the length and the silkiness of his wool. He was called Soyeux (silky), and put to a most carefully selected flock of ewes more or less similar to himself. Amongst his numerous progeny of the first year there were only two ewe lambs perfectly like him. The best individuals of his offspring during the first and the following seasons were inbred with Soyeux himself, and one might have expected to be soon in possession of a new breed like Soyeux. Owing, however, to very many instances of reversion, it took fully eight years before any signs of constancy were visible. For more than thirty years it was considered doubtful whether the new Mauchamp flock would ever attain to that constancy of inheritance without which no breed has any value. It is worthy of notice that such lustry-woolled sheep, as the ram Soyeux is said to have been, have not unfrequently been seen in other merino flocks, such as the French Rambouillets, and in some Victorian flocks. The Victorian lustre wool far surpasses that of the Mauchamp in quality, but I have not heard lately whether the establishment of such a lustre-wool merino flock has been successful in Victoria. It is evident that the elements of such a silky combing wool with good length must be latent or dormant in the merino. Some of the Ercildouns strongly reminded me of the samples of Mauchamp I have seen. The Mauchamps do not seem to be looked upon with favour, although their wool is exceedingly soft and silky. In all probability their transmitting power is too uncertain. To my knowledge they have never been imported into Australia, whilst other French merinos have been used with great success-particularly the Rambouillets.

From what has been said about the laws of inheritance, and the different circumstances under which the effects of them may be desirable to us or otherwise, we must naturally conclude that animals of near relation will transfer their qualities better than others, because they are descended from the same ancestors and their constitutions are similarly organised.

The highest authorities on sheep-breeding whose works I have read, and with some of whom I have come in personal contact, were unanimous in declaring that by carefully selecting suitable animals out of the same flock, by mating them judiciously, and by eventually inbreeding them, far better results may be obtained than by frequent freshenings up of blood. The following breeds, excellent in every respect, may serve as instances that it is possible to obtain results, desirable in every respect by inbreeding, although it is maintained by some that cohabitation of near relations produces in the human family weak constitutions, idiocy, &c.