68(3 EXPEEIMENT STATION RECORD. 



older tumor cells than in those of more recent origin. The nucleus of 

 the cells which are filled with spores is rich in chromatin considerabl}' 

 enlarged and shows a decided proliferation. In some of the spores a 

 progressive metamorphosis of their nuclear substance occurs, as the 

 result of which 2 or 3 nuclei appear in the place of one. In the 

 tumors produced by Plasuwd'iojjhora hrai<sic<£, the phagocj^tosis which 

 was caused b}' the presence of the organism seemed alwaj^s sufficient 

 to bring about the ultimate destruction of all the parasites. 



White scour in calves {FarmerM Gaz.^ oO {1900). Xo. o^p- ^^)- — Ten 

 cows were divided into 2 lots of 5 each. In lot A the cows were fed 

 in the ordinary way, but the calves, as soon as ])orn, were put in a 

 clean house, and fed 4 times a day a small quantity of new milk with 

 a little warm water in it. Each calf was fed separately, and after 3 

 weeks received a little separated milk and barlev meal. In lot B the 

 cows were fed for al)out a month before calving on 10 lbs. of bran and 

 meal mixed in the morning and evening. The milk from these cows 

 was given to their own calves, each calf being fed 3 times a day for a 

 fortnight. After this period they were fed twice a day on fresh milk 

 mixed with separated milk and barle}" meal. 



The results of these experiments indicate conclusively the impor- 

 tance of careful feeding of calves and constant attention to cleanliness. 

 Ko calves died from lot A while 2 died out of lot B, and of 14 calves 

 treated in the ordinary Avay. 9 died. 



A report on tuberculosis of cattle, L. Pearson and M. P. Rav- 

 ^.^^^.{PeHnsylmnUi Dej>t. Ayr. Epf. 1899, 2>t. 1, JW- 333-533).— The 

 authors present a general historical account of the development of 

 knowledge concerning this disease, together with a discussion of the 

 means and extent of distribution, prevalence, importance, and meth- 

 ods for controlling this disease. From numerous tests made bv the 

 Pennsylvania Live Stock Sanitary Board, 12.2 per cent of cattle in the 

 State reacted to tuberculin. 



Experiments were conducted with guinea pigs which were kept in a 

 compartment in the lower end of nosebags attached to tuberculous 

 cows. The guinea pigs were thus forced to breath the air expired by 

 the tuberculous animals. Twelve guinea pigs were used in these 

 experiments, and were exposed for periods varying from 2^ to 26 

 hours. None of them became infected. Two lots of guinea pigs 

 inoculated with tuberculosis were kept in light and dark boxes, respec- 

 tively. One lot was placed in a box with a glass front and the top and 

 back made of wire netting covered with white cloth. The other lot 

 was placed in a box of equal size made of wood painted black inside 

 and a wire netting Imck covered with l)lack cloth. The guinea pigs in 

 the light box lived from 5^ to 6 days longer than those in the black 

 box. This experiment indicates the effect of light in checking the 

 development of tub(M"culosis. 



