OTTO GLASER. 



membrane, not infrequently lies at a considerable distance beneath 

 it. All this is indicative of a region differentiated from the re- 

 mainder of the egg. 



Is copper demonstrable in this layer? None of the direct 

 methods could give an unequivocal answer, though the triple- 

 nitrite test did reveal a few black granules similar to the black 

 beads found in the membrane. This might be considered a dem- 

 onstration of copper if the displacement of an occasional pigment 

 granule in the process of sectioning could be altogether set aside. 

 But there are other considerations. 



The fertilization of egg fragments has been reported by numer- 

 ous investigators, including myself C13 1 ), yet the correctness of 

 these observations has been doubted because some egg fragments 

 are incapable of fertilization. The difference is accounted for in 

 the work of Chambers, 3 who finds that fragments derived exclu- 

 sively from the interior of the egg can not be fertilized, whereas 

 those containing a fair portion of the cortex respond like the origi- 

 nal egg. This evidence, if not compelling, at least indicates more 

 immediately than any other the physiological distinctiveness of the 

 cortex and the necessity of cortical materials in fertilization. 



Now, certain secretions of the egg are likewise necessary. This 

 was first shown by F. R. Lillie ('13 2 ), and subsequently by my 

 sterilizations with charcoal ('21 4 ). A logical combination of our 

 two necessities traces the secretions to the cortex. But are they — 

 or perhaps better, their forerunners — really there? For the nor- 

 mal egg this has not been demonstrated, nor is the cortex, in all 

 probability, their only location; for egg fragments, with chorion 

 and membrane both removed, the inference appears less hazardous. 

 The concentration, then, of the secretions, or their forerunners, in 

 the cortex of the egg may be assumed as a not unreasonable work- 

 ing hypothesis. 



On the basis of isolable precipitates, Miss Woodward ('18) and 

 I ('21 5 ) have contended that these secretions contain at least two 

 separate substances — a lipolytic ferment and a material which ag- 

 glutinates spermatozoa. The immediate problem consequently 

 narrows down to this : Is copper demonstrable in precipitated 

 lipolysin and agglutinin? 



3 See Lillie's "Problems of Fertilization," p. 264. 



