382 Xaohide Yatsu. 



the fibrous ray stops at X, while the non-tibrous ray reaches the 

 perii^hery. The formation of any aster in the alveolar plasm shoAvs 

 that non-hbrons rays nsually precede librous ones. I have already 

 mentioned a case in which the rays (non-fibrons) of a very yonng 

 sperm aster were brought to view only after thorough extraction 

 (PL II, Figs. 27, 28 and 32, 33) (cf. Wilson, '99, p. 14). 



Rays are formed not only under the influence of the centrioles 

 but also under that of many other structures. In the blastomeres 

 of a tel( ost, Coveyonus alhus, for instance, a special group of rays 

 is formed along the inner side of the karyomere groups (PL III, 

 Fig. 56). A section of an egg of Aster las accidentally crushed when 

 alive shows distinct rays along the flow of alveoles (cf. Ziegler, 

 '04, p. 550). Parasite asters on the rays have been seen in the egg 

 of Asterias (PL III, Fig. 55). 



The distribution of the pole rays seems to be influenced by that 

 of the hyaloplasm in the cytoplasm as is seen in the fan figure 

 ("Facherkern"). In etherized eggs of Asterias, one often observes 

 funnel-shaped asters. 



In many cases the rays are formed in homogeneous plasm^^ (quite 

 different from Biitschli-Rhumbler's explanation). In Fig. 5G (PL 

 III) the central ends of the rays are in a homogeneous hyaloplasmic 

 area. Fig. 58 (PL IV) is the central aster of tire first maturation 

 figure in the nuclear area (residual mass of the germinal vesicle). 

 It is noteworthy that the sperm aster can enter the nuclear area 

 without being distorted (PL IV, Fig. 59). Quite often one finds 

 the sperm aster half in. 



Rays have a peculiar tendency to elongate toward any formed body, 

 such as chromosomes, or degenerating nucleoli. Fig. 60 (PL IV) 

 shows a maturation aster. Three groups of rays are here, as it 

 were, fishing chromosomes. In the middle one it should be noted 

 that a ray is bent so as to meet the chromosome. Apparent splitting 

 of rays may be due to the above characteristic as in the case of 

 Fig. 61 (PL IV), where one of the asters has precociously divided. 



"This is more likely intra-mieroscopioally or potontially alveolar (Veidovsky, 

 '88; Wilson, '00), yet none the less it appears homogenous in the living and 

 granular in the fixed state. Rhumhler calls this ''Protoplasnia ohne erkennbare 

 Waben" ('00, pp. .^,44, r^A^^). 



