556 BULLETIN OF THE 



So far as has yet been ascertained, this peculiarity has no present 

 importance, and I know of nothing which affords the least ground for 

 anticipating such a discovery. 



Several observers have raised the question what may be its historic 

 meaning. Rabl's theory of a coenogenetic origin has been already con- 

 sidered. From a comparison with studies on conjugation among Infu- 

 soria, Biitschli has arrived at the conclusion that the globule has a 

 palingenetic signification. The formation of polar globules is a part of 

 the process of fecundation, and is equivalent to the elimination (mutual 

 interchange) of " nucleoli " in the temporary conjugation of Infusoria, 

 and the increasing evidence of their universal occurrence renders such 

 an (historically) early origin the more probable. Certain objections to 

 this interpretation, partly anticipated by Butschli, have been empha- 

 sized by Whitman, who, besides, finds evidence of the reasonableness of 

 another theory in the " absence of such cells (equivalents of polar glob- 

 ules) among the Infusoria." It may be said in addition, that the cell 

 nature of the polar globule, being now definitely settled, precludes that 

 strict comparison of its substance with the " secondary nucleus " of 

 Infusoria to which a purely nuclear composition (as at first claimed by 

 Biitschli) would have presented no obstacle. 



The opinion, first defended by Strasburger, that the polar globules 

 have their counterparts in the " canal cells " of plants, opened the way 

 for the theory (compare p. 463) which Whitman has ably advocated. 

 The polar globules are a relic of the primitive or asexual mode of repro- 

 duction. A gamic cell-generation is followed by a line of agamic gener- 

 ations, the last of which are the polar globules. 



This is the only view which offers the least explanation of the fact 

 that these globules are cells. I believe it forms an important step 

 toward the solution of their meaning ; but it does not explain why this 

 agamic process of cell-proliferation reappears after a long period of quiet 

 growth on the part of the ovum. The signification which most naturally 

 suggests itself in this connection is that they are representatives of once 

 functionally active ova ; that the renewed proliferation was formerly a 

 means of increasing the number of the reproductive parts, just as in the 

 formation of the spermatozoa the mother cells, after a period of growth, 

 finally break up into a number of individual elements. In the case of 

 the male elements natural selection has operated, through the multiplied 

 chances of their failing of the opportunity to execute their normal func- 

 tion, for the preservation of the functional integrity of every individual, 

 and even for a great increase in the number of the elements which 



