VETERINARY MEDICINE, 277 



several chapters of this work deal with the history of the disease iu Britain ; 

 the disease as it occurs in other countries of Europe, and especially in Ger- 

 many and France; symptoms and pathology of the disease; account of a case 

 of scrapie seen in Germany; the structure and possihle developmental stages 

 of the sarcocyst and their relation to the spread of the disease ; symptoms 

 exhibited by animals heavily infected with sarcosporidia ; the action of the 

 sarcocystin, the toxin produced by the sarcocyst ; the mode of spread of sarco- 

 sporidiosis from animal to animal in carnivorous animals ; method of spread 

 of sarcosporidiosis in graminivorous animals; observations as to the presence 

 of sarcocysts in the muscles of apparently healthy sheep ; and epizootiology. 



In conclusion tlie author states that he believes scrapie to be caused by a 

 heavy infection with sarcosporidia. This heavy infection appears to be brought 

 about by the system of breeding in vogue in the regions where scrapie is in 

 evidence, namely, the keeping up of the ewe stock by means of the ewe lambs 

 derived from the 2-year-old ewes, this being the age period at which scrapie 

 occurs most abundantly, and which results in the heavily infected mothers 

 passing on a heavy infection to their progeny. He has obtained no evidence, 

 epizootiological or pathological, that the disease is spread by the ram. 



Among the considerations that have led the author to conclude that scrapie 

 is due to a heavy infection with sarcosporidia are the following: The sarco- 

 cyst is always present in the skeletal muscles of scrapie sheep in large num- 

 bers, and the more advanced the case the larger is the number of the sarco- 

 cysts present. Pruritus (or itching), the chief symptom in scrapie, can be 

 reproduced in rabbits by the injection into them of sarcosporidial emulsions. 

 Careful clinical examinaton of typical cases makes it highly probable that the 

 paretic phenomena of the disease are due to a primary muscle lesion. There 

 is an absence of any condition of post-mortem, except extensive sarcosporidio- 

 sis, sufficient to or of a nature likely to cause the phenomena observed in the 

 disease, and no single view can explain so well the symptomatology and 

 epizootiology, etc., of the disease as this. 



Treatment of the disease appears to be useless and the author recommends 

 that the affected animal be sent to the butcher at once before the sarcocysts 

 have become verj' numerous and the animal emaciated, that the ewe stock be 

 kept up from the progeny of the older ewes, and that the progeny of the 2-year- 

 old ewes, and possibly of the two-crop ewes, be sent to the butcher. Diseased 

 animals should at once be killed to prevent any possibility of their being used 

 as breeding stock. 



In an appendix reference is made to a report" and a paper (E. S. R., 30, p. 

 783) by Stockman relating to the subject, and to the work on Johne's disease 

 by Twort and Ingram noted on page 273. 



A glossary of terms is appended. 



Diseases of swine with particular reference to hog' cholera, C. F. Lynch 

 iPJiiladclphia and London, 191 Jf, pp. Ufl, flgs. 120). — This work deals espe- 

 cially with hog cholera and the manufacture and use of autihog-cholera serum. 



In the first part of the work (pp. 17-83) the author discusses the various 

 breeds of swine. Under the headings of infectious diseases of swine, he first 

 takes up hog cholera (pp. 84-510) at considerable length, and then briefly con- 

 siders the other infectious diseases (pp. 511-534). Discussions of diseases of 

 the digestive tract, respiratory tract, kidney and bladder, heart, skin, nervous 

 pystem, organs of locomotion, organs of generation, parasitic diseases, and sur- 

 gical diseases (pp. 535-709) follow. 



A chapter on castration by G. R. White (pp. 710-728) is appended. 



" Bd. Agr. and Fisheries [London], [Vet. Dept.] Ann, Rpts. Proc. 1909, p. 22. 



