BUEEAU OF ANIMAl, INDUSTRY. 241 



The first dose given by the slow method — that is, where very small 

 doses are used — is 0.4 cubic centimeter, or 20,000,000 bacteria. The 

 dose is increased by 0.2 cubic centimeter at each dose, so that at the 

 seventh dose the number of bacteria injected is 80,000,000. 



The l.ar^e doses cause a decided temporary drop in resistance of 

 the animal, or a negative phase, which is manifested by depression, 

 increased discharge, and swelling at the point of inoculation. This is 

 succeeded in a few days by increased resistance or increased positive 

 phase. When the smaller doses are given, the short, mild, negative 



Ehase is soon succeeded by the positive phase, and thus immunity is 

 uilt up without the usual depression, etc., to wliich the owner objects 

 so much. Efforts are now being made to reduce the number of vacci- 

 nations to the minimum. 



The so-called stock cultures of pus-forming organisms have also 

 been used instead of those freshly isolated from the pus material in 

 order to compare the curative effects, and in nearly every instance the 

 stock cultures fail to give as good results as the more virulent organ- 

 isms isolated from each case. 



mVESTIGATIONS OF POULTRY DISEASES. 



Lesions closely resembling those of tuberculosis were discovered 

 about the heads, necks, and wings of some pigeons wliich had been 

 forwarded to the bureau because of the growth of certain lumps or 

 tumor-like masses in their subcutaneous tissues. These growths 

 developed until they had finally reached the size of chestnuts and 

 were firmly encapsulated, A little pressure after an incision had 

 been made caused the spherical contents of the sac to roll out as a 

 sohd ball. A transverse section of this growth showed that it was 

 made up of successive layers of yellowish material. An examination 

 of this material under the microscope revealed the presence in large 

 numbers of acid-fast bacilli wliich closely simulated avian tubercle 

 bacilli. A closer examination of these rods, however, showed that 

 they were not typical of the acid-fast bacilli usually found in tuber- 

 cular material from fowls. Pappenheim's test demonstrated that 

 this bacillus was acid-fast only, not acid- alcohol fast. The growths 

 were therefore probably not tubercular. 



This "lumpy" disease of pigeons can be developed in other pigeons 

 in about 10 days, whereas genuine tuberculosis of pigeons requires 

 three weeks and more for its development in experimental cases. It 

 therefore appears that this quite common disease of pigeons, usually 

 pronounced tuberculosis on account of having acid-fast bacilli in the 

 cheesy material, must 1 e studied further in order to determine the 

 relationship between th s aiToction and that of avian tuberculosis. 

 A similar disease has been observed about the heads of several 

 Minorca fowls. 



THE GERMICIDAL AND KEEPING PROPERTIES OF RAW AND PASTEUR- 

 IZED MILK. 



The germicidal property of raw milk and pasteurized milk was 

 compared by inoculating each kind with a given volume of various 

 kinds of bacteria which could bo readily recognized upon agar plates 

 by their pigment or peculiar characteristics of growth. Bacterial 

 counts were made of the raw and pasteurized milk before inoculating 



23165"'— AGB 1911 16 



