No. 2.] THE OVARIAN EGG OF LIMULUS. 195 



In such cases the carmine or safranin stains the chromatin 

 granules of the nuclei ; and when this is followed with Lyon's 

 blue, everything in the cytoplasm, except these red nuclei, 

 stains a deep blue, making indeed handsome preparations. I 

 should certainly hesitate, therefore, to regard everything as 

 archoplasm in the sense in which Boveri used that term, which 

 stains blue with this when combined with carmine and safranin. 

 An e.xamination of the plates of Miss Foot ('96), where the 

 effect of this stain is extensively represented, would tend to 

 increase rather than diminish such a reluctance. When asso- 

 ciated with carmine or safranin, these are the specific stains. 

 The value of the Lyon's blue lies in this, that it brings promi- 

 nently into view those areas containing no chromophilous 

 granules ; and for this purpose it is very convenient. In the 

 first period of growth of the egg of Limulus it has been 

 pointed out that both germinal vesicle and cytoplasm contain 

 these chromophilous granules, this body alone being devoid of 

 such granules. When eggs of Limulus are properly preserved, 

 there are none of those irregular areas in the cytoplasm which 

 Miss P'oot has found in the egg of Allolobophora by means of 

 this stain. 



The vitelline-body having been shown to possess, in its earli- 

 est stages, all of the features of the centrosome and sphere, 

 and to be, in fact, the centrosome of the dividing oogonia, it 

 remains to show that the body found in the cytoplasm in later 

 stages is the same centrosome. For this purpose the plates 

 will afford better evidence than a labored description. The 

 figures being drawn with a camera with the same magnifying 

 power, show the body in the various stages of the growing egg. 

 It can be seen that even in advanced stages of the egg the 

 body often presents the fundamental features seen in the earli- 

 est stage, and often very nearly the features of a typical cen- 

 trosome and sphere (Figs. 42-48, 6-j, 68, 82, 89, 114). These 

 are characterized by the presence of a strongly refractive spher- 

 ical body often surrounded by a clear zone, which again is 

 surrounded by a zone of metaplasm (archoplasm Boveri) and 

 provided with a system of radial fibers which can be seen 

 to traverse the metanlasmic zone and to extend far out into 



