74 SCHULTZ AND JORDAN: STUDIES IN ANAPHYLAXIS 



While this table must be regarded as more or less provisional, 

 it represents perhaps a first step in that analysis of the phenomena 

 involved, which must necessarily precede any quantitative treat- 

 ment of the problem before us, namely the investigation of the 

 rate of increase of a given type of organisms, as a function of 

 their physical properties. So much, perhaps, has been made clear, 

 that the subject is closely related, on the one hand to the theory 

 of observational error, and on the other to the theory of value. 

 This last point, on closer inspection, seems to offer some specially 

 alluring prospects for further study. Mathematically the prob- 

 lem at this point takes the form typical of the calculus of varia- 

 tions: In an evoluting system of the kind considered, certain 

 functions must tend to assume such form as to make the prob- 

 abilities of a fatal encounter a minimum. 



If on the other hand we contemplate the subject of our 

 " judgment of value" in its philosophical relation to human life 

 again we are met by a number of interesting suggestions. 



But at this point my subject merges into the realm of sentiment, 

 which one is reluctant to enter. 



PHARMACOLOGY. — Physiological studies in anaphylaxis. VI. 

 The reaction of the opossum to horse serum. W. H. Schultz 

 and H. E. Jordan, Hygienic Laboratory. Communicated 

 by J. W. Kerr. To appear in a Bulletin of the Hygienic 

 Laboratory. 



The intact non-sensitized opossum reacts only slightly to large 

 intraperitoneal doses of horse serum, this action being evidenced 

 chiefly by signs of abdominal cramps. The anesthetized non- 

 sensitized animal records a temporary fall, and sometimes a 

 slight rise of blood pressure and a change in the rate and force of 

 respiration when injected intravenously with 0.0025 cc. of horse 

 serum per gram body weight. 



The intact opossum sensitized toward horse serum reacts very 

 energetically to intraperitoneal and intravenous injections of 

 serum, as is evidenced by the passage of urine and feces, the fre- 

 quent yawning, the slowing and deepening of the respiration, vom- 

 iting, muscle weakness, and signs of abdominal cramps. The 



