not treated in any way. The 18 serum-treated pigs and the 8 untreated pigs were then placed in the same pen with the 4 pigs which had been made sick of hog cholera. The 4 pigs which were inoculated with hog cholera all died. The 8 untreated check pigs all contracted hog cholera from the 4 inoculated ones. The 18 pigs which were given serum and which were confined in the same pen with the 4 original sick pigs and with the 8 untreated pigs which became sick remained perfectly well and were finally turned over to the officials of the stockyards company upon the completion of the experiment on September 17, 1910. The experiment was witnessed by representatives of the Nebraska Agricultural Experiment Station at Lincoln and of the Nebraska Swine Breeders' Association, as well as by representatives of several different agricultural papers published in Nebraska.

The use of carbolized or phenolized blood, as described in my last annual report, has been continued during the year. The later results confirm the earlier observations in showing that the virus of hog cholera may remain in contact with comparatively strong solutions of phenol for weeks without noticeable impairment of its virulence. There seems to be little doubt that phenolized blood will gradually come into general use in connection with the "simultaneous method," as the presence of the phenol prevents the development of putrefactive bacteria and does not destroy the virus of hog cholera. This will enable practitioners to keep virus on hand for a reasonable length of time.

Considerable study has been given to the effect of different preservative agents on the virus of hog cholera as contained in the blood of sick hogs. In addition to the continued study of phenol much attention has been devoted to thymol and formaldehyde. The results with regard to these, however, are not yet complete. Aside from the desirability of having some means of preserving the virus for use in simultaneous inoculations, it is also desirable to have some means of preserving disease-producing blood which is to be used later for hyperimmunization. Phenol is not satisfactory for this purpose, but it is hoped that some efficient germicide which is efficient against ordinary bacteria, but which does not materially affect the virus of hog cholera, will be found suitable for this purpose. Some attention has also been given to different preservatives for serum. These observations are not yet complete.

The study of the immunity possessed by young pigs has been continued, but up to the present time the data obtained are not sufficiently conclusive to warrant a definite statement of results.

WORK FOR THE COMING YEAR.

During the ensuing fiscal year it is proposed to make a study of the changes taking place in meat during cold storage, the object being to decide upon the best conditions of storage and to ascertain whether or not meat becomes unwholesome after storing for a long time.

A study of the egg breaking and packing industries has also been undertaken and is in charge of a committee consisting of the chiefs of the Pathological, Animal Husbandry, and Biochemic Divisions. Plans have been made for carrying on this investigation in cooperation with a similar organization in the Bureau of Chemistry.

Other lines of investigation mentioned in this report will be continued, special attention being given to an investigation of the cereal and water in sausage and to methods for the standardization of tuberculin.

THE ZOOLOGICAL DIVISION.

The Zoological Division, under Dr. B. H. Ransom, chief, has been engaged, as heretofore, in the investigation of parasitic diseases of animals and in the study, collection, and determination of animal parasites.

ROUNDWORMS OF SHEEP.

The investigations relative to stomach worms and other roundworms parasitic in sheep have been continued. Experiments not yet completed are in progress which are intended to give data on the reduction and prevention of parasitic infection by rotation of pastures.

It has been found that the embryos of the hair lungworms of sheep pass out of the body of infested animals with the feces, and it is probable that infection is spread as commonly through this means as through the sputum.

Important facts have been determined bearing upon the life history of the gullet worm of sheep and cattle.

TAPEWORMS OF SHEEP.

Investigations have been begun relative to the fringed tapeworm, which in the western United States apparently does more damage than any other internal parasite of sheep, the stomach worm and the nodular worm being as yet rare and of little importance in the Rocky Mountain and Plains regions.

GID IN SHEEP.

It has been definitely determined by experiment that the tapeworm stage of the gid parasite will develop in coyotes. The coyote is therefore a factor in the spread of this disease as well as the dog. Except for a center of infection in the State of New York, the disease still appears to be enzootic in this country only in Montana. Two publications relative to gid have been issued during the year, one (Bulletin 125) rather technical in character, the other (Circular 165) of a more popular nature.

Gid apparently was introduced into New York through infested sheep dogs imported from Europe, and it was on account of the danger of further occurrences of this kind that B. A. I. Order 176 of November 25, 1910, was issued, providing for the quarantine and inspection of imported sheep dogs.

To determine the presence or absence of tapeworm infection, fecal examinations were made of 52 imported dogs quarantined under the provisions of Order 176. Eighteen of these dogs were found to be infected with tapeworms and received appropriate treatment before they were released from quarantine. The total number of fecal specimens examined, including those taken subsequent to treatment to determine the success of the treatment, was 80. In several instances

repeated treatments were necessary before the tapeworm eggs disappeared from the feces. The quarantine and treatment were conducted under the supervision of the Quarantine Division.

SHEEP SCAB.

The favorable results obtained in the experiments with tobacco dip without sulphur, in cooperation with the Kentucky Agricultural Experiment Station, have been confirmed by the reports of practical dippings in the field by bureau inspectors. Dipping solutions containing 0.07 per cent of nicotin were used. Reports have been received relative to the dipping of 20 lots of sheep infected with scab, comprising 35,515 head, and 1 lot of exposed sheep, comprising 2,950 head. Four of the lots were reported as not exposed to reinfection. after dipping, 11 were returned to infected range or pasture, and it was not known in the case of 6 lots whether they were exposed or not. The disease was reported cured in all cases, with no reappearance as determined by inspections made after a lapse of time varying from 1 to 6 months in different instances.

As a result of these investigations the use of tobacco dips without sulphur has been permitted in the official dipping of sheep for scabies.

CATTLE MANGE.

Under the supervision of Dr. W. E. Howe, of this bureau, further experiments in the treatment of cattle mange with a kerosene and soap preparation have been carried out.

On April 14 two lots of mangy cattle (11 and 15 respectively) were treated in a spraying machine with the preparation diluted to give a strength of 8 per cent of kerosene. Five weeks after spraying mites were found in 2 cattle of the first lot and 6 cattle of the second lot.

On April 15 two lots of mangy cattle (11 and 13) were treated in a spraying machine with the preparation diluted to give a strength of 7 per cent of kerosene. Five weeks after treatment mites were found on 2 animals in each lot.

On April 18 two lots of mangy cattle, of 15 each, were dipped in the preparation diluted to give a strength of 7 per cent. Five weeks after treatment mites were found on 1 animal in each lot.

Two lots of mangy cattle (14 and 15) were dipped April 19 and 20, respectively, in the preparation diluted to give a strength of 6 per cent. Five weeks after treatment one lot was apparently free from mange; in the other lot 2 animals were found to be infected.

From these experiments it may be concluded that the kerosene preparation in question is not efficacious in the treatment of cattle mange when used as a dip in a strength of 7 per cent or less or as a spray in a strength of 8 per cent or less, a single application of the remedy being given in either case, even though it is used in the spring of the year, at which time mangy cattle tend to improve in condition without treatment.

INVESTIGATIONS RELATIVE TO TICK ERADICATION.

Bulletin 130, recording the results of two years' investigations relative to the life history of the cattle tick and other points bearing on tick eradication, which were conducted in cooperation with the

veterinary department of the Alabama Polytechnic Institute, was issued during the year.

In experiments with arsenical dips it was found that no appreciable ill effects were produced on calves dipped during the period from the latter part of June to the latter part of October, repeated at intervals of two and three weeks in a dip composed of 10 pounds of arsenic trioxid, 25 pounds of sodium carbonate, 1 gallon of pine tar, and 500 gallons of water.

Two series of experiments were conducted with a proprietary arsenical dip, one during the summer in southern Texas, the other during the fall in Oklahoma. The dip proved efficacious in destroying ticks when applied twice with an interval of 10 days between dippings and at a dilution which gave an equivalent of 0.22 per cent arsenic trioxid in the dipping bath.

Experiments on a small scale with an arsenical dip prepared in concentrated form by the Biochemic Division were sufficiently favorable to warrant field trials of the preparation.

In all of the experimental work with dips, the Biochemic Division has cooperated in devising improvements in the preparation of the dips and in supplying analyses of the dips used.

Investigations have been begun in cooperation with the Biochemic Division relative to the absorption of arsenic through the skin of cattle dipped in arsenical dips and the effect of such absorption upon cattle and upon subsequent tick infestation.

INVESTIGATIONS CONCERNING PARASITIC PROTOZOA.

Further work has been done upon a trypanosome common in the blood of American cattle, but apparently nonpathogenic, and a bulletin recording this work has been prepared for publication.

Interesting and important facts have been determined relative to certain morphological details in the Sarcosporidia.

Fortunately for the live-stock industry of the United States, no exotic trypanosome disease has succeeded in becoming established in this country, although animals as stock and for menageries have been brought here in the past more or less indiscriminately from all parts of the world. Past good fortune, however, does not necessarily promise immunity for the future. As illustrations, it may be noted that importation of animals from Europe went on for several hundred years before that highly injurious pest of live stock, the horn fly, became established (since 1886) in this country, and that dourine was brought in only a few years ago, the first outbreak causing considerable damage before the disease was eradicated. It is therefore highly important that all possible practicable precautions should be taken to guard against the ever imminent danger of introducing trypanosome diseases with shipments of animals from abroad, especially in view of the fact that these diseases, as a rule (dourine being as exception), are transmitted by winged insects and hence are almost impossible to eradicate if they become established. In order to supply information relative to trypanosomes, in a readily available form, a paper is in preparation, and nearing completion, in which are given the diagnostic characters, life history, host animals, and geographic distribution of all known species of trypanosomes.

INDEX-CATALOGUE OF MEDICAL VETERINARY ZOOLOGY.

The author index of this catalogue has been completed, parts 27 to 34 having been issued during the year, and part 35 having since appeared. Part 36, containing additions and corrections, has been prepared and sent to the printer. In reporting the completion of this index it may be noted that this is one of the most important and valuable reference works on the subject of parasitology ever published and has been greatly in demand not only in this country but also abroad.

PARASITES OF HOGS.

Some work has been done on the kidney worm, stomach worms, and ascarids of hogs. More extensive investigations of these important parasites are contemplated for the ensuing year.

MISCELLANEOUS.

Numerous autopsies were performed on various animals, wild and domesticated, and examinations made for the presence of parasites; a large number of specimens sent in by the field force of the bureau and by other correspondents were examined and identified; the usual amount of correspondence relative to parasitic diseases was received and replied to, and other routine matters have received attention.

An important work on the nematodes parasitic in the alimentary tract of cattle, sheep, and other ruminants, which has been in preparation for several years, has been published as Bulletin 127.

Several new species of parasites discovered in the course of investigations carried on in this division have been described and the descriptions turned over to the United States National Museum for publication.

THE EXPERIMENT STATION.

The work at the bureau's Experiment Station at Bethesda, Md., under Dr. E. C. Schroeder, superintendent, during the past fiscal year has been of the same general character as in former years, consisting of independent investigations, investigations in cooperation with other divisions of the bureau, and the provision of facilities for the other divisions to make investigations of a kind that require farm and field conditions not obtainable within the limits of the city. During the year most of the work in animal husbandry was transferred to the newly purchased farm at Beltsville, Md., and it is proposed henceforth to confine the work at Bethesda mainly to investigations of animal diseases.

TUBERCULOSIS INVESTIGATIONS.

Tuberculosis was the subject of the more important investigations of the year. Studies relative to the protective treatment of cattle against this disease have been continued, and, while nothing radically new has been discovered, the results obtained with various methods of bovo-vaccination against tuberculosis are encouraging. No treatment that will give cattle a practically valuable immunity against tuberculosis without the inoculation of living tubercle bacilli has yielded promising results, and there seems to be no reason for changing the formerly expressed view that the time has not yet come to jus