132 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



is apparently the minimum amount that can be depended on to 

 remove all the bots belonging to both species. It also appears 

 that the administration of linseed oil in connection with doses of 

 carbon bisulphid diminishes the efficacy of the latter drug against 

 bots and ascarids. 



MISCELLANEOUS INVESTIGATIONS ON ANIMAL PARASITES. 



Investigations on the possible relation between swamp fever in 

 horses and intestinal parasites have been carried on in cooperation 

 with the Health of Animals Branch, Canadian Department of Agri- 

 culture. These investigations have as yet led to no definite con- 

 clusions and are still in progress. The investigations on the gape- 

 worm of chickens have been continued. 



Studies have been made of the effects of substances obtained from 

 the tissues of Asca7^is, A^icylostoma^ sheep tapeworms, and other 

 })arasites upon the blood of various animals, and in some cases these 

 substances have been found to have a hemolytic action; also in cer- 

 tain instances an agglutinating effect upon red blood corpuscles. 

 It has also been determined that experimental animals in certain 

 stages of trichinosis are highly sensitive to injections of blood serum 

 from another trichinosis animal. Highly interesting results have 

 been obtained in experiments with anaphylactic and precipitin reac- 

 tions in which extracts of various species of parasites have been 

 tested against one another. A preliminary report on the hemolytic 

 action of Ascaris extracts has been published. 



During the fiscal year 131 imported sheep dogs were examined for 

 the presence of parasites transmissible to live stock. Of these 62 

 were free from intestinal parasites as determined by fecal examina- 

 tions and 69 were infested. Twenty-two showed the presence of tape- 

 worms and received anthelmintic treatment before release from quar- 

 antine. In one case the tapeworms expelled by treatment proved o 

 be of the species known as the gid tapeworm. It is because of the 

 danger of this tapeworm to livestock, especially sheep, that imported 

 sheep dogs are subjected to quarantine. This is the first case of gid 

 tapeworm that has been encountered since the inauguration of the 

 quarantine, a number of years ago. 



A study has been made of several species of flukes and the results 

 prepared for publication. A comprehensive paper on the tapcAvorms 

 of dogs and other carnivores, some of which are transmissible to 

 human beings and live stock, has been published, also a report of 

 observations on intestinal trichinae. The portion of the Index-Cata- 

 logue of Medical and Veterinary Zoology relating to nematodes 

 which has been prepared in cooperation with the Public Health Serv- 

 ice is now being printed. 



MISCELLANEOUS DIVISION. 



The Miscellaneous Division, of which Dr. A. M. Farrington is 

 chief, has continued its work relating to the personnel of the bureau 

 and to veterinary education. 



BUREAU PERSONNEL. 



At the beginning of the fiscal year the persons in the employ of the 

 bureau numbered 5,221. During the year there were 1,556 additions, 

 made up as follows: Appointments, 1,458; transfers from other 



