444 ' BULLETIN OF THE 



globules ill non-fecundated eggs soon after their exclusion (less accurately 

 to be traced before exclusion). In the living eggs one sees two eleva- 

 tions (cumuli) of clear protoplasm, often, though not always, at diametri- 

 cally opposite points of the surface of the yolk. One arises at the expense 

 of the aster which is fellow to that from which arises the female pronu- 

 cleus. This aster forms an inequal karyolytic figure, of which the small 

 aster becomes the cumulus which produces the first polar globule; the 

 second arises subsequently ; both are very small, and disappear quickly. 

 In using staining reagents one finds two nuclei at this pole of the egg. 

 The more superficial is the one which by dividing forms the polar glob- 

 ules ; the other is the female pronucleus. This method of the forma- 

 tion of polar globules is, so far as I know, quite unique. 



The results published by Fol ('77'') in his paper " Sur le Commence- 

 ment de I'Henogenie chez divers Animaux," have been in part given 

 already in the reviews of his preliminary notes. When he says (p. 441) 

 that the internal half of the first " amphiaster de rebut " remaining 

 in the yolk becomes a complete amphiaster, one might possibly be in- 

 clined to infer from the statement that there was some evidence of the 

 conversion of the internal half of the '* nuclear plate " into a veritable 

 nucleus as one of the steps in the process of the formation of the second 

 archiamphiaster. This view, however, is entirely unsupported by what 

 follows. In fact Fol seems to leave no chance for the possibility of such 

 an event, for he says distinctly in this paper (p. 448) : " Then the in- 

 terior aster is converted into an amphiaster in the following manner. 

 Butschli's filaments, instead of retiring toward the centre of the aster, 

 elongate anew% and the varicosities disappear by being drawn out. These 

 filaments again constitute a spindle (Fig. 7), one extremity of which is 

 found at the centre of the internal aster, while the other point of conver- 

 gence for the filaments corresponds to the point of contact of vitellus and 

 first polar globule. In the middle of these filaments new varicosities are 

 formed." There is nothing in the figure cited, nor in any other of those 

 given by Fol, which fully warrants the name am^Amster, since no trace 

 of a radial influence at the outer pole of the second spindle, save the 

 spindle fibres, is visible, to say nothing of a complete aster at this point. 

 A complete spindle is present ; a complete amphiaster is not. 



On another point Fol gives (p. 447) somewhat more extensive informa- 

 tion than hitherto. He still insists that with the starfish the first am- 

 phiaster does not give rise directly to the polar corpuscles. " If," he 

 says, " one treats an egg with reagents a few minutes after the first am- 

 phiaster is formed, one no longer finds an amphiaster, but a compact 



