208 BULLETIN OF THE 



tion and of wide extent ; its rays straight ; its centre not quite homo- 

 geneous. 



The spindle, especially, appears very different from the condition pre- 

 sented in the preceding stage. It is well defined, long, and embraces 

 few thick fibres, which are arranged in a close, narrow bundle. The 

 middle third of the fibres seems somewhat thicker than the terminal 

 thirds, but no other indication of either equatorial or lateral zones can 

 be made out. From the position of the centre of the outer radiate fig- 

 ure, which is still at some distance from the surface, it may be inferred 

 that the stage here shown antedates the formation of the equatorial 

 nuclear plate; however, the gradual thickening of the spindle fibres 

 toward the equator may perhaps be interpreted as a differentiation in- 

 itial to the formation of the plate. 



The vitelline granulations, otherwise evenly distributed, are largely 

 excluded from the stellar areas, and are less numerous about the animal 

 pole than in the vegetative half of the sphere. 



The phenomena connected with the production of the second polar 

 globule are, from this point on, nearly a repetition of those of the first 

 globule : the formation of the equatorial zone and its separation into 

 halves ; the translation of the whole figure along the animal radius ; the 

 ultimate attainment of the surface by the centre of the peripheral star ; 

 the consequent modification of its form ; the deepening constriction 

 which cuts down upon the spindle between the two lateral zones ; the 

 formation of a cell-plate ; the gradual disappearance of the half-spindle 

 in the polar globule, and a corresponding indistinctness in the vitelline 

 half-spindle, — all these occur, with only slight modifications, in the 

 manner already traced in the earlier stages.. There are, however, some 

 points worthy of more special attention. The second polar globule is 

 generally smaller than the first. The relative sizes, which are subject to 

 considerable variation, may be most easily comprehended by an inspec- 

 tion of the figures. Then, too, a certain obliquity of the parts about 

 the animal pole, already alluded to (p. 182), is often observable during 

 the formation of the second globule. This is well exhibited by Fig. 66. 

 The internal half of the spindle is so obliquely placed as to appear almost 

 parallel to a tangent at the animal pole ; the long axis of the globule is 

 also oblique, but is oppositely inclined, so that a sharp bend is caused in 

 the course of the interzonal filaments. The centre of the deeper star 

 thereby attains a more superficial position than would otherwise be pos- 

 sible, and it may be that we are to look to this fact for an explanation 

 of the peculiar appearance. I am inclined to think, however, that the 



