374 OTTO GLASER. 



15. Bi-subnitrate gave no reduction. 



So far as these tests go, and they were repeated several times, 

 it seems likely that reducing substances are absent, and that if 

 proteins are present, their concentration is too low to give the 

 ordinary reactions in their usual form. The opalescence observed 

 upon the addition of acids, and the yellow color gotten in the 

 xanthoproteic test, indicate possibly minute traces of protein 

 but these may come from traces of the egg jelly. 



With all the tests that made such experiments possible, the 

 secretion was afterwards tested as to its agglutinating property, 

 and was found in every case to still possess this power, tests 3, 

 4, and 5. No exact quantitative comparison as to the agglu- 

 tinating strength before and after boiling was made. Lillie 

 states ('I3 1 , p. 557) that the agglutinin when boiled and then 

 allowed to stand at 95 for 30 minutes is destroyed in large part, 

 and almost entirely if kept at this temperature for 66 minutes. 

 In some of my experiments the secretion was brought to the 

 boiling point, in others it was boiled 5 minutes. The color change 

 noted always occurred, but the agglutination power appeared 

 undiminished. Both of these results are described in Lillie's 

 paper ('I3 1 ). 



As to the nature of the purple substance, I may say that even 

 if its formation, and presumably with that, the abstraction of 

 something from the original solution makes no measurable dif- 

 ference in the agglutinating power of the secretion, this material 

 may nevertheless be significant in other connections. My reasons 

 for suggesting this are that when a sperm suspension is added 

 to the secretion, traces of this purple color appear; when dilute 

 sperm suspensions are killed by heat the same color is seen; in 

 concentrated suspensions the red dominates over the blue; and 

 in still more concentrated suspensions the color is like that of 

 port wine. This same color also appears in desiccated eggs as 

 well as sperm. From these facts the thought lies near at hand, 

 that we are here dealing with the production of a compound 

 specific for Arbacia. Corresponding experiments with Asterias 

 do not give this color, nor have I gotten it with oyster sperm. 

 On the other hand, Asterias sperm as well as egg-secretion turn a 

 slight salmon-color when boiled. With the exception of these 



