gray rock on which they are laid, it is only by a rare chance if you find a nest without flushing the old bird. The young nighthawk is about as broad as long, and, unlike the callow young of most birds, it is covered from head to foot with a thick coat of down.

On our return we anchored the first night in a little harbor at Allons' Key, where two small fishing-boats had already taken refuge from a threatening squall. We saw the ruins of several huts on this island, and the remains of a small grove of cocoanut trees, which had been blown down in the destructive hurricane of September, 1884. The place was so infested by mosquitoes that this little settlement had to be abandoned. It rained heavily in the night, but our men took an early start, and awoke us the next morning at five by announcing the discovery of a

FIG. 6.-FRUIT AND FLOWERS OF THE SEVEN-YEAR APPLE (Genipa clusiifolia). (One half natural size.)

"loggerhead's track." The beaches had been leveled by the rain, so that any new impression could be readily seen. The turtle had ascended the beach to a point above high tide, had stirred up the sand, leaving a great heap over her eggs, and returned to the water but a short time before we landed. This was shown by the ebbing tide, which had retreated only a short distance from her last tracks. The eggs were laid in a bunch, and covered with sand a foot and a half deep. There were

just one hundred and thirty-nine of them. They resemble a white rubber ball, an inch and a half in diameter. The sea-turtle's eggs have a peculiar flavor, but are very palatable. The glair becomes tough and leathery by boiling, and is always thrown away. The breeding-season of the loggerhead (Chelonia caretta) lasts from May well into August, according to the statement of our guide, who also said that they deposited eggs several times in this period, producing as many as one hundred and eighty at the first laying, and perhaps no more than two or three at the last. The natives make a business-like search for these eggs each year, and sometimes surprise the female turtle on the beach. When she has once begun the egg-laying process, it has to be finished, even if she is turned on her back and made a prisoner immediately after. The extraordinary egg-producing power of these animals is all that preserves them from immediate extinction.*

FIG. 7.-THE WILD SAPODILLA (Sapota achras). (Three fourths natural size, showing some of the old fruit and the new flowers and leaves.)

Large forest-trees, such as pine, cedar, and mastic, which grow on Abaco, do not occur on the keys. We find here, however, smaller trees and shrubs in great variety. Besides those already mentioned,

* Some time ago a large grouper was speared by a fisherman off Sand Key near Nassau, and twenty-two young loggerheads were found in its stomach. This fish was doubtless feeding along the shore, and had evidently snapped up the young turtles just

there are three palmettos, called the "silver" and "thatch-top palms," and "hog-cabbage"; "sea-grape" (Coccoloba uvifera); the "sevenyear apple" (Genipa clusiifolia); Malvaviscus arboreus, a handsome shrub, with red flowers, resembling a small hollyhock; mangrove (Rhizophora mangle); wild sapodilla (Sapota achras); and many others equally characteristic. Land-snails are very common on some of the islands, and the omnipresent lizards (Annolis) were the only reptiles which we met with.

The Genipa or seven-year apple is very abundant along the shores of the islands just above high-tide mark. It sends up from the ground slender brittle stems a few feet high, bearing creamy-white flowers and a hard, yellowish-green fruit, which is inedible. The leaves are dark green and highly polished.

The wild sapodilla is equally common, and attains the height of a small tree. The axillary flower-clusters appear a little in advance of the leaves, which in June add a touch of the brightest spring green to every thicket. The fruit, which is not edible, is covered with a rusty-brown skin, and is usually terminated by the long persistent style. The cultivated sapodilla forms a good-sized tree, and appears to grow spontaneously wherever it has been introduced. It differs from the former chiefly in point of size and in the superiority of its fruit. Possibly the wild form is the parent stock from which the other, with its sweet, pulpy fruit, has been derived; but I have been unable to gather any facts relating to this point. A milky juice flows freely from the wounded bark of the sapodilla-trees, forming a viscid gum, which the negroes use as bird-lime. It is also noteworthy that the Isonandra gutta, a Malayan tree, from the juice of which the gutta-percha of commerce is obtained, is also a member of the Sapotacea or Sapodilla family.

These islands have been largely colonized from the South, principally perhaps from Cuba; and the Gulf Stream and other agents, which have brought the plant-germs thither, have carried them also to the keys and coast of Florida, where they may have first become established. The seed-eating birds, finches and starlings, which are common on Abaco and many of the small islands, serve also as important distributors of grains and seeds of other plants. The great number of shrubs bearing edible berries may be partially accounted for in this way. The annual hurricanes, on the other hand, are certainly powerful agencies in scattering seeds over wide areas. Knowing the frequency of their occurrence and their long duration, we can see how by this means alone an island would soon acquire a rich and varied flora.

as they were making their début in the water. Thus it seems that these animals have to contend with enemies which are even more formidable than man, and it not surprising that this valuable and once staple product of these islands is fast becoming a luxury.

THE PSYCHOLOGY OF JOKING,

By J. HUGHLINGS JACKSON, M. D., F. R. S.

PUNNING, I think, does not receive enough attention. In spite of

Dr. Johnson's well-known dictum, we should not despise punning. Sydney Smith says that it is the foundation of all wit. Supposing three degrees of evolution, I submit that punning is the least evolved system of joking, that wit is evolved out of punning, and that humor is evolved out of wit. Everybody has heard of Sydney Smith's remark -that it requires a surgical operation to get a joke into the head of a Scotchman. But he spoke without distinguishing. The Scotch have a great appreciation of those highly-evolved jocosities displaying the humorous, although, no doubt, a scorn of simple, lowly-evolved jocosities, such as plays on words. It is difficult to form a conception of a Scotch punster. Yet I have heard an Aberdonian, a physician of worldwide reputation, make a pun.

Punning is well worthy of the psychologist's attention. I seriously mean that the analysis of puns is a simple way of beginning the methodical analysis of the process of normal and abnormal mentation. This, I think, I can easily show. Vision is stereoscopic: in a sense it is slightly diplopic, for there are two dissimilar images, although there seems to be but one external object, as we call it. To borrow the ophthalmological term, we can say that mentation is "stereoscopic "; always subject-object, although we often speak of it as single ("states of consciousness," etc.). Just as there is visual diplopia, so there is "mental diplopia," or, as it is commonly called, "double consciousness." Now I come back to punning. We all have "mental diplopia" when hearing the answer to a riddle which depends on a pun-" When is a little girl not a little girl?" Answer: "When she is a little horse (hoarse)." The feeble amusement we have in the slightly morbid mental state thus induced is from the incongruous elements of a "mental diplopia." The word "hoarse " rouses in us the idea of a little girl who has taken cold, and the same-sounding word "horse" rouses in us the idea of a well-known quadruped at the same time. We have the sensation of complete resemblance with the sense of vast difference. Here is, I submit, a caricature of the normal process of all mentation. The process of all thought is "stereoscopic" or "diplopic," being the tracing of relations of likeness and unlikeness.

To call punning a slightly morbid mental state may be taken as a small joke, but I do not think it very extravagant to describe it so ; it certainly is not if it be a caricature of normal mentation. A miser has been defined as an amateur pauper; the habitual drunkard is certainly an amateur lunatic; and in the same style of speaking we may say that—well, we will say that punning is playing at being foolish; it is

only morbid in that slender sense. The word "play" carries us forward in a slightly different direction. Jocosities of all degrees of evolution (1) puns, (2) witticisms, and (3) humorous statements-are the "play of mind"; play in the sense in which the word has been used in the remark that the "æsthetic sentiments originate from the play impulse." A further definition of play as thus used is given in the following quotation from Spencer: "The activities we call play are united with aesthetic activities by the trait that neither subserve, in any direct way, the processes conducive to life."* There would be a great intellectual advance-due, I presume, to internal evolution-when man began to value things for their beauty apart from their use, one sign of his having "got above" his mere animal self. For it showed that, over and above mind required for mere animal existence, he had some surplus mind for greater ends of life. So I contend that our race owes some respect to the first punster. For the dawn of a sense of the merely ridiculous, as in punning and the simplest jokes, shows the same thing as the dawn of æsthetic feeling-surplus mind, something over and above that required for getting food and for mere animal indulgence. All the more so if punning be that out of which wit and humor are evolved. It is not a good sign if a man be deficient in humor, unless he have compensation, as Wordsworth had, in a sense of the sublime, or in great artistic feeling, or in metaphysical subtlety. The man who has no sense of humor, who takes things to be literally as distinct as they superficially appear, does not see fundamental similarities in the midst of great superficial differences, overlooks the transitions between great contrasts. I do not mean because he has no sense of humor, but because he has not the surplus intellect which sense of humor implies. Humor, being the "play" of mind, is tracing deep, fanciful resemblances in things known to be very different. This is "playing" at generalization, and is only a caricature of the same kind of process which made Goethe declare that a skull is a modified part of a vertebral column.

Now I am about-not really digressing from what I have just said -to say something which sounds very paradoxical: that persons who are deficient in appreciation of jocosities in their degrees of evolution, are in corresponding degrees deficiently realistic in their scientific conceptions. One would infer this a priori. Every child knows that a man born blind has no idea of light; but the educated adult knows, too, that the congenitally blind have no notion of darkness. And I think that observation confirms what a priori seems likely-that pari passu with the evolution of the sentiment of jocosity (playing at unreality) is the evolution of power of realistic scientific conceptionfrom sense of the merely ridiculous with parallel realistic conception of simple things, up to sense of humor with parallel realistic conception of complex things. But we must be on our guard not to take "Principles of Psychology," vol. ii, p. 627.