552 FOOT AND STROBELL. 



Photo 82, vignetted section (3/x) of an egg at about the same stage of develop- 

 ment as that of Photo 81, one polar ring shown in the section. This photo was 

 taken to show osmophile granules in the cytoplasm and in the polar rings. Many 

 of them have undoubtedly faded, as the preparation was not examined for many 

 months after fixation. In fresh material many more are present. Preparation 

 unstained and mounted in glycerine. Fixative, Hermann's fluid. 



Photo 83, the same section shown in Photo 82 after the preparation had been 

 stained with iron-hsematoxylin. A close examination of the two sections will show 

 that both have been taken at nearly the same focus; the largest osmophile granules 

 of Photo 82 can be seen in this stained preparation, but the smaller ones (especially 

 those in the polar rings) are obliterated by staining the archoplasm around them. 

 In the stained preparations they are no longer black, but have retained a brownish 

 yellow tint, which makes a sharp photo. A close comparison of the two sections 

 will show that many of the small granules not blackened by the osmic in Photo 82 

 have stained intensely with the hasmatoxylin. They resemble the granules which 

 have aggregated to form the polar rings {cf. Photo 84 for the granular structure 

 of the polar ring). 



Photo 84, vignetted section (3 \x) of an egg with the first cleavage spindle at the 

 metaphase. The section passes through one polar ring near the periphery of the 

 egg. The granular form of the archoplasm which is aggregated as a polar ring is 

 clearly shown in this photo. Fixative, chromo-acetic. 



Photo 85, vignetted section (3/11) of an egg at the same stage of development 

 shown in Photo 81. This section through one polar ring further illustrates the 

 inconstancy of the form of the polar ring. (See under Photo 81.) Fixative, 

 corrosive sublimate, followed by platinum chloride. 



