Anaphylaxis in Immune Animals. 



181 



till well on in April. The diurnal variation, so marked at the 

 surface, is almost completely abolished at this level, all the year 

 round, and this is a circumstance which greatly favors animals 

 with an imperfectly developed heat regulating mechanism, such 

 as the woodchuck possesses. 



Records of the air temperature taken at the Ithaca station 

 of the U. S. Weather Bureau, situated about half a mile from the 

 burrows, show that in 1912 the coldest month of the year was 

 January, and in 1913, February, the average mean temperatures 

 for the first four months being as follows : 



Jan. Feb. March. April. 



1912 16. 3 0 F. 21.4 28.8 44.5 



1913 34-7° F. 23.2 36.8 48.1 



Notwithstanding the fact that the weather in these four months 

 was much milder in 1913 than in 1912, the temperature at the 

 depth of four feet, in March and April 1913, as indicated by the 

 thermograph, was about 2° F. lower than in the corresponding 

 months of 1912. The snowfall, however, was greater in 1912 than 

 in 1913 and this will probably explain the apparent anomaly. 



Jan. Feb. March. April. 



Snowfall in inches, 1912 ... .9.0 6.7 12.3 0.5 



Snowfall in inches, 1913 .... 2.1 5.0 2.9 0.8 



In 1912, although the air was intensely cold, the comparatively 

 thick layer of snow effectively retarded the radiation of heat from 

 the surface of the ground. 



It is interesting to note, then, that the woodchuck awakes from 

 the hibernating state and becomes active just about the time the 

 temperature of its surroundings has reached the lowest point for 

 the year, and it would appear that some cause other than the 

 temperature or carbon dioxide factor is at work to bring this result 

 about. 



115 (811) 

 Anaphylaxis in immune animals. 

 By Richard Weil, M.D. 



[From Cornell University Medical School.] 



In his general review of anaphylaxis, Besredka 1 stated that an 

 injection of horse serum into guinea pigs produced hypersensitiza- 



1 Kraus and Levaditi's "Handbook," 1911, p. 248. 



