188 BULLETIN OF THE 



Beale's carmine. One may perhaps seek an explanation of this appear- 

 ance in a want of uniformity in the imbibition which takes place as soon 

 as the egg comes in contact with the ammoniacal carmine. This view 

 is, moreover, strengthened by the appearance of the exposed, thickened 

 layer of protoplasm which envelops the yolk. For in the region of 

 these spots the outline becomes less dark and conspicuous, as though 

 a softening of the envelope had here allowed a portion of the proto- 

 plasm to become less dense, and therefore feebly refractive. On the 

 other hand, a subsequent falling in of the surface at these points — 

 such as might naturally be expected, from the above explanation, to 

 follow when the object is placed in a more dense fluid, like glycerine — 

 has not been observed ; on the contrary, these areas continue to be 

 raised conspicuously above the common level of the surface of the yolk. 

 The protuberances have the appearance of quite naked, protruding por- 

 tions of clear protoplasm. Whether they are anything more than the 

 result of artificial ruptures of the cortical substance of the vitellus it is 

 difficult to say. That they may be due to the presence of spermatozoa, 

 which have already penetrated the yolk, is perhaps not impossible ; but 

 it appears to me unlikely from the irregularity in the size and configu- 

 ration of the spaces, as well as from the entire absence of any regular 

 arrangement (stellate) of the granules in the surrounding protoplasm. 

 I have not discovered any specially modified central portion, nor any 

 difference between the spots and the immediately surrounding proto- 

 plasm in the facility with which staining is effected. I have not ob- 

 served anything of this kind in eggs of more advanced stages. 



What has been said of this earliest stage is based, unfortunately, on a 

 limited number of specimens ; and, although my notes are unequivocal in 

 declaring the eggs in question to be fresh-laid, I have not been able to 

 entirely free my mind from the suspicion that, after all, they are much 

 older than I have given them credit for being. The very considerable 

 size of the amphiaster is perhaps in itself enough to suggest the possibility 

 that they were nearly ready to effect the first cleavage, and that the 

 aster is, consequently, the first cleavage amphiaster. 



The considerations, however, which incline me to the belief indicated 

 above are, in addition to the notes proving the freshness of the eggs, the 

 following : — 



1. The almost exactly central position of the amphiaster. This, it is 

 true, would hardly be a safe criterion to distinguish this amphiaster from 

 that of a second arcAmmphiaster, (as we shall presently see,) but is, it 

 seems to me, very strong evidence that we have not to do in this case 



