460 BULLETIN OF THE 



escape observation, cannot be considered strange, since similar changes 

 resulting in the obscuration of polar globules have been frequently ob- 

 served. Subsequent statements furnish the only ground presented for 

 such a conclusion. The authors found, namely, on eggs taken from fe- 

 males ready for oviposition, that there was constantly a large, flattened 

 lenticular nucleus near the active pole in the superficial layer of trans- 

 lucent protoplasm. This is comparable, they believe, with the germina- 

 tive vesicle of birds' eggs, and with that which 0. Hertwig has figured 

 for mature batrachian eggs ; it is, however, smaller than the latter, but 

 larger than, and not comparable with, the deeply situated nuclear struc- 

 ture (Eikern) shown by Calberla in his Figs. 3 and 4. This germinative 

 vesicle, from its position and size, just covers the dark spot called by 

 Calberla " inner micropyle." After fertilization the place of the vesicle 

 is occupied by a clearer mass, but it is difi&cult to determine its limits 

 on hardened eggs. 



Before the protoplasmic "Zapfen" ("Dottertropfen" of Calberla) dis- 

 appears, one observes that a globular, granular body arises within its 

 previously clear mass, and that it is ejected (second polar globule) from 

 the " Zapfen " as the latter sinks again into the yolk. 



In Clepsine the germinative vesicle gives place, according to Whitman 

 (78", pp. 13-49, Figs. 1-9, 60-67), to a bistellate figure, which is 

 called "archiamphiaster," while the egg is still in the ovary. The 

 details of the process were not observed. In the earliest stages seen 

 the axis of this archiamphiaster is inclined to that radius of the egg 

 which passes through the centre of the amphiaster, but later this obli- 

 quity disappears, and the axis of the figure coincides with the radius. 

 The most conspicuous parts are the two poles, encircled as they are 

 with well-defined radial lines which extend out into the densely packed 

 yolk spheres some distance beyond the polar '* areas." The central part 

 of the area is more deeply colored with carmine than its peripheral part. 

 Between the two poles is a more or less spindle-shaped space free from 

 yolk spheres. This corresponds very nearly with the germinative vesicle 

 in size. Within this space the radial lines of the two stars are con- 

 tinuous from pole to pole. These interstellate lines appear to diff'er in 

 no essential way from the other radial lines. In only two preparations 

 was anything found comparable to Strasburger's Kernplatte, and in 

 these cases of so doubtful a character that they were omitted from the 

 drawings. Whitman is inclined from this to regard with favor FoFs idea 

 that the spindle fibres are identical with the stellate rays, and only 

 appear different since they are surrounded by different media. The 



