36 DEPARTMENTAL REPORTS. 



and found unsatisfactory. Reports from several sources indicate 

 that the ticks can be affected by substances given internally to the 

 cattle on which they are parasitic, but tests of such substances have 

 given no encouraging results at this station. This entire question will 

 receive further attention in the future. 



Toward the end of last summer the cattle ticks in the tick fields 

 had become so numerous that it was necessary to spray the fences and 

 adjoining ground every few days, and even with this precaution the 

 cattle in the fields near the tick fields could not be kept altogether 

 clean. In some instances the young ticks crawled from 20 to 30 feet 

 along the ground and up the sides of fences and buildings, where they 

 collected in clumps of several thousands each. Ticks from these 

 clumps in elevated positions could easily be blown considerable dis- 

 tances by moderately strong winds. The solution used for spraying 

 consisted of tar, carbonate of soda, arsenic, and water. It was very 

 effective in destroying the young ticks which had not become attached 

 to a host, but it killed less than 75 per cent of the ticks of all sizes on 

 the cattle which were dipped in it. 



An interesting occurrence in connection with the tick experiments 

 was the accidental presence of the parasites on two kittens, which 

 were confined in a small house in the tick field. The house also con- 

 tained a number of guinea pigs, which remained perfectly clean. The 

 ticks developed very slowly on the kittens, and the latter unfortunately 

 died before any of the ticks matured. The extreme irritation of the 

 skin and the loss of blood were largely responsible for the death of 

 the kittens. 



EXPERIMENTS WITH RABIES. 



A number of animals reported to have been bitten by rabid dogs 

 were received at the station, and were kept in confinement and under 

 observation. 



Several experiments regarding rabies were made in conjunction 

 with the pathological division, o One horse which was bitten and some 

 sheep which were inoculated with material from rabid animals suc- 

 cumbed to the affection after showing characteristic symptoms. 



OTHER WORK. 



Some work was done in connection with the antitoxine experiment 

 to determine the loss in the number of red-blood corpuscles as the 

 result of frequent blood drawings, and the rapidity with which the 

 animal's system is able to correct the loss by the formation of new cor- 

 puscles. Time was also given to a study of the character of the 

 newly formed corpuscles, and to the possible modifications in the 

 number and character of the white corpuscles of animals which receive 

 periodic injections of septic material. Investigations along this line 

 will be continued as time will permit. 



Animals and facilities were provided the division of zoology for 

 the further investigation of the sheep-scab question, and to test vari- 

 ous drugs for the removal of parasites from the stomachs and intes- 

 tines of sheep and hogs. * 



The pathological division was provided with animals and facilities 

 for the investigation of the following diseases: Braxy and pseudo- 

 tuberculosis in sheep, vulvitis of cattle, and an infectious disease 

 among the cattle of a local asylum. A number of specimens of black- 

 leg vaccine were also tested for the same division on sheep and 

 guinea pigs. 



