102 The Unity of the Organism 



contains nearly the same number of equivalents of the 

 precipitate. 



In his well known work Blood Immunity and Blood Re- 

 lationship, G. Nuttall has applied this principle more widely 

 to the animal kingdom than any one else. 



(c) Comparative Chemistry of the Sperm of Different 

 Species of Fishes 



Several biologists are impressed with the importance of 

 knowledge in this field as bearing on philosophical natural 

 history. No physiologist has so far as I am aware, ventured 

 quite so far into the realm of prophecy with reference to it 

 as has E. Abderhalden. He points out the possibility of 

 increasing the number of attributes now recognized as dis- 

 tinguishing not only species but individuals through a sys- 

 tematic and concerted carrying out of researches already 

 begun in this field, and foresees the time when biochemistry 

 will play a leading role in problems of racial descent and 

 taxonomic affinity. 23 The march of research in tjie decade 

 since Abderhalden made these forecasts, has undoubtedly 

 been toward a fulfillment of them, at least as touching bio- 

 chemical distinctions between individuals. Thus C. Todd 

 has very recently given a useful summary of what has been 

 done up to the present hour on the comparative chemistry 

 of the blood as revealed by the methods here being consid- 

 ered, and an account of an exceedingly interesting rcsarch 

 of his own. 



The chemico-zoological researches standing next in in- 

 terest and importance to those on the blood are the well 

 known ones inaugurated by Miescher and continued by Kos- 

 sel and his students, on the spermato/oa of fish. Miescher 

 discovered in the sperm of the salmon a group of protein 

 substances called by him protamines, which arc said not 

 to have been found as yet elsewhere than in fish sperm. 



