92 



OTTO GLASER. 



2. Copper Absorbed by the Egg Membrane. 



With hematoxylin the membrane of the exposed egg is bluer 

 than the normal. The triple-nitrite test, however, is more con- 

 vincing. In optical sections of the surface one no longer finds 

 individual black beads strung on a thin thread, but a heavy con- 

 tinuous black line. Even the highest powers fail to resolve the 

 continuity. It seems very clear, indeed, that potassium-copper- 

 lead nitrite is more abundant than in normal membranes. 



On this basis it is possible to understand one of Lillie's results. 

 If an excess of copper in the membrane alters it so that sperma- 

 tozoa are not able to penetrate as easily as under normal conditions, 

 we should expect " a certain virtue in mass action in the presence 

 of this inhibitor of fertilization" {loc. cit., p. 129). I noted ex- 

 actly the same virtue ('15) in connection with eggs which had been 

 exposed to calcium. This particular point and its meaning have 

 both been overlooked in subsequent discussions. 



3. Copper Absorbed by the Cytoplasm. 

 Inside the exposed egg there are differences in the same sense. 

 The number of black granules after the nitrite treatment is greatly 

 increased. As a whole and in sections the exposed egg is dis- 

 tinctly darker than the normal. Copper evidently passes inward 

 through the membrane and diffuses generally through the cyto- 

 plasm. 



4. Copper Absorbed by the Cortex. 



If, as Lillie's experiments indicate, the cortex contains "un- 

 saturated " copper-avid material, one may expect very considerable 

 differences in the cortical zone. As a matter of fact, the triple- 

 nitrite test brought to light black beads similar to those seen in 

 and immediately under the normal membrane ; they were decidedly 

 more numerous than in normal eggs and gained in distinctness by 

 heating. Furthermore, the blue zone which in normal eggs resists 

 resolution by all the methods employed now differentiates slightly 

 with both potassium ethyl xanthate and potassium ferrocyanide. 

 With the first, the blue acquires a greenish tint and becomes sep- 

 arated from the egg membrane by an exceedingly narrow yet dis- 

 tinguishable yellowish layer; with the second, a very thin brown 

 band intervenes between the original blue and the membrane. 



