Nov., 1921.1 CYTOLOOICAL STUDIES ON PORPHYRA TENERA. 211 



both ends it assumes a lemon shape. The membrane which covers 

 the carpogonium forms a protuberance due to the process of the 

 latter which is considered as a rudimental trichogyne. The car- 

 pogonium contains the nucleus and chromatophore of usual type. 

 Berthold (I) has pointed out that the mature carpogonium ready 

 for fertilisation has no trichogyne and it is formed when the visiting 

 of spermatium is delayed. I have had no occasion to verify his 

 observation. The spermatium which was liberated from the anther- 

 idium attaches itself to the trichogyne as is illustrated in Fig. 10. 

 Many spermatia occasionally are seen to be attached to a trichogyne 

 (Fig. 11). 



The critical moment of passing of male nucleus through tricho- 

 gyne toward the female nucleus and the subsequent nuclear fusion 

 were not able to follow, owing to the want of suitable material. 

 This gap is hoped to be filled up in future research. The fertilised 

 carpogonium divides into eight cells ; the process of division follows 

 the same course as in the case of spermatium formation. Each cell 

 of the octant thus formed, after assuming a spherical shape becomes 

 carpospore. As to the internal structure of the mature carpospore 

 special description will not be needed, for it follows the same type 

 as that of the vegetative cell (Fig. 9). The carpospore escaped from 

 the thallus soon germinates under favourable condition as fully 

 described by Okamura and coUaboraters (8b) and Yendo (13). The 

 nuclear phaenomenon of the sporling is not worth mentioning as it 

 follows the usual way. Details on this subject will be made public 

 in another day. 



The first and second divisions of the zygote-nucleus have not 

 been traced because of the want of the suitable material. But the 

 divided nuclei were often found as shown in Text-figs. 1-9 which 

 worth to mention. In Text-fig. I, two daughter nuclei are deliniated, 

 each of which is situated in the both extremities of a zygote, and in 

 Text-fig. 2, another small nucleus is observed by the side of the lower 

 nucleus. Text-figs. 3-8 illustrate the two-cell stage of the antheridium ; 

 Text-fig. 3 shows two cells, each containing a single nucleus, while 

 Text-fig. 4 shows large and small nuclei in the upper cell ; in Text- 

 fig. 5 both cells contain large and small ones ; Text-fig. 6 shows one 

 large and two small nuclei in the upper cell ; Text-fig. 7, large and 

 small nuclei just divided in the upper cell ; Text-fig. 8, pairs of large 

 and small nuclei in the upper cell, and one large and three small 

 ones in the lower cell. Text-fig. 9 shows a tetrad, in which each 



