132 PRIMITIVE OVA. 



Size of Piimitive oTa in Size of nucleus of Primitive 



degrees of micrometer scale ova iu degrees of micrometer 



with F. ocul 2. scale with F. ocul 2. 



10 8 



13 8 



13 8 



14 7 



15 7 



13 7i 



11 8 



16 51 



12 7 



10 7 



15 6 



13 6 



12 7 



This series brings out the result I have just mentioned with 

 great clearness. 



In one case we find a cell has three times the diameter of 

 the nucleus 16 : 5J; in another case 10 : 8, the nucleus has 

 only a slightl}^ smaller diameter than the cell. The irration- 

 ality of the ratio is fairly shewn in some of my figures, though 

 none of the largest cells with very small nuclei have been 

 represented. 



The nuclei are granular, and stain fairly well with haema- 

 toxylin. They usually contain a single deeply stained nucle- 

 olus, but in many cases, especially where large (and this 

 independently of the size of the cell), they contain two nucleoli 

 (PL XT. fig. 14 c and 14* d), and are at times so lobed as to give 

 an apparent indication of commencing division. 



A multi-nucleolar condition of the nuclei, like that figured 

 by Gotte\ does not appear till near the close of embryonic 

 life, and is then found equally in the large ova and in those 

 not larger than the ova which exist at this early date. 



As regards the relation of the jDrimitive ova to each other 

 and the neighbouring cells, there are a few points which de- 

 serve attention. In the first place, the ova are, as a rule, 

 collected in masses at particular points, and not distributed uni- 

 formly (fig. 14 a.) The masses in some cases appear as if they had 



^ EiiticicJdungsgeschichte der Unkc, PI. i. fig. 8. 



