EGG SECRETIONS OF ARBACIA AND ASTERIAS 471 



in other words, Arbacia blood has no effect on the ' spermophile 

 group' (LiUie). 3) Loeb ('14) dissolved the jelly from the eggs 

 of S. purpuratus by means of to HCl. These eggs were no longer 

 able to agglutinate sperm, but could be fertilized. From this 

 experiment and from the fact that some species can be fertilized 

 by sperm of other species, even though those sperm are not 

 agglutinated by secretions from the eggs, Loeb concluded that 

 ''The substance which is responsible for cluster-formation is not 

 necessary for the process of fertilization." Lillie ('15) repeated 

 this experiment, using Arbacia instead of Strongylocentrotus, 

 and found, as soon as the acid was entirely washed away, that the 

 eggs continued to secrete an agglutinin. It is possible that in 

 Loeb's experiment the agglutinin was so dilute as to give only a 

 momentary reaction which was overlooked or that the presence 

 of acid interfered with the reaction. 



2. General chem-ical properties of the egg secretion, a. Proper- 

 ties shown by qualitative chemical tests. Glaser ('14 b) under- 

 took a qualitative analysis of both Arbacia and Asterias secre- 

 tions. He found them neutral to litmus and unable to reduce 

 Fehling's solution. Various tests for protein failed to give a dis- 

 tinct reaction, although there were indications that protein might 

 be present in very small amounts. For instance, while the 

 "xanthoproteic test gave no precipitate, the solution turned dis- 

 tinctly yellow." He was also unable to obtain a precipitate 

 either by boiling or by adding alcohol. 



The writer confirmed all of these points. It was also found 

 that the secretion does not dialyze through a collodion sac. 

 Benedict's test for sugar was applied, as being more sensitive 

 than Fehling's, but gave negative results. Since the xantho- 

 proteic test produces a yellow color, we may infer the presence of 

 tyrosine, phenylalanine, or tryptophane. 



It was not deemed advisable to carry out a complete chemical 

 analysis of the secretion. Qualitative tests, however, indicated 

 the presence of both carbon and nitrogen. 



b. Properties shown by x-radiation. In 1914 the writer was 

 able, cooperating with A. Richards, to study the effect of x-radia- 

 tion on Arbacia egg secretion. An account of these experiments, 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 26, NO. 3 



