I 82 OTTO GLASER. 



equal volume of normal eggs. Both errors really operate against 

 any a priori idea that the jelly is responsible for the removal of 

 the salts. If then the result is clear cut nevertheless, it would 

 appear that the experiment is decisive. 



Two such comparisons are given in Table V. 



TABLE V. 

 CHLORINE PER c.c. IN TERMS OF AgNO 3 n/zo. 



Sea-Water Sea-Water 



Sea-Water with with 



Control- Normal Eggs. Chorion-free Eggs. 



eggs .2 c.c. eggs .2 c.c. 



Alter 30 minutes n.o - = 10.9 - - = n.o 



sea-water 14.8 c.c. sea-water 14.8 c.c. 



eggs .2 c.c. eggs .2 c.c. 



After 2 hours n.o = 10.9 - = n.o 



sea-water 10 c.c. sea-water 10 c.c. 



A further test seemed desirable. If the jelly takes up the salts, 

 it should be possible to demonstrate their presence in the chorion. 

 The method was that of Macallum 7 in which the reagent, n/io 

 AgNO 3 is acidulated, per liter, with 25 c.c. of 60 per cent. HNO 3 

 in order to avoid any confusion that might result from possible 

 phosphate precipitates or combinations of the silver with proteins 

 or their constituent parts. 



The eggs after being carefully drained were gradually trans- 

 ferred to absolute alcohol, and after hardening, subsequently 

 treated with Macallum's reagent for half an hour. After this 

 they were placed on a glass slide, cleared in glycerine under a 

 cover slip, and exposed to direct sunlight for 30 minutes. The 

 distribution of the reduced silver is shown in Fig. 2. 



FIG. 2. Arbacia egg with chlorides indicated in chorion. 



" Macallum, A. B., Die Methoden der Biologischen Mikrochemie. Abder- 

 halden's Handb. d. Bio-chem. Arbeitsmethoden, 1912, p. noo. 



