382 Hilda Klncaid : 



It will be obvious from the above table that muscular tissue 

 shows a surprising uniformity in its phosphorus content 

 throughout the aninuil kingdom. Calculated in the dry sub- 

 stance the figures show the percentage to be slightly greater in 

 the fishes and oysters than in the higher animals, but calcu- 

 lated in the ash the variations show no parallelism with degree 

 of development. We may state therefore that phosphoi-us of 

 this concentration, viz., .38 to .5, is apparently a normal and 

 essential ingredient for contractile tissue. 



D. — ^Experiments to determine Distribution and Evolutionary 

 Significance in Nerve Substance. 



Analyses of brain substance of the various classes of Vei-- 

 tebrates were made. It is unfortunately impossible to get 

 enough nerve tissue for analysis in the Invertebrates. 



For results see table p. 383. 



The experiments as far as they went show the brain sub- 

 stance in the examples of the various vertebrate classes ex- 

 amined to have practically the same percentage of PoO.- in the 

 dried. Thus again in nerve substance there appears to be no 

 parallelism between P2O5 content and evolutionary develop- 

 ment. 



E. — Experiments to determine the Distribution and Evolu- 

 tionary Significance in the Exoskeleton of Invertebrates. 



Analyses of the exoskeletons of Invertebrates, comprising 

 examples from the groups Porifeira C'oelenterata, Mollusco- 

 idea, Echinodermata, Arthropoda and Mollusca were made. 



For results see table p, 383. 



