270 THE BOTAMCAL MAGAZINE. [Vol. xxiv. No. 287. 



Farmer and Moore (2), Grecoire (3) &c, contractions of 

 nuclear substance occur more than once in the maiotic phase. 

 This fact too strengthens the possibility that the contraction 

 phenomenon or synizesis is not biologically an essential process, 

 but a result of strong metabolic activities. 



The nucleus in the prophase is often found provided with 

 several dwarf-nucleoli beside the ordinary large one. They are 

 placed close to the large nucleolus or scattered about between 

 the chromatin-threads (Figs. 8, 10), a phenomenon, probably 

 related to the metabolic activity in the nucleus and to the 

 nutrition of chromosomes. 



In the next stage the chromatin-threads increase in length 

 and thickness, and the synaptic ball begins to loosen (Fig. 7). 

 and the chromatin-threads stretch out over the nuclear cavity. 

 The paired threads become closer and closer, till finally they 

 unite themselves into one (Fig. 8). As has been pointed 

 out by Overton (9), the moment of actual union seems 

 to vary in different cases : a case of pre-synaptic fusion 

 was also observed by Stomps (10), and my case is one 

 of the post-synaptic union. Thus the true synapsis in the 

 meaning of the word and the chief contraction take place 

 separately. The united threads grow more and more, and 

 stretch themselves in the entire nuclear cavity. Then they 

 reappear as separated threads (Fig. 9), and their segmentation 

 follows. Thus twelve gemini of twisted threads make their ap- 

 pearance. They become shorter and thicker, and take a ring- or 

 X- shape (Figs. 10, 11). At the later stages of the diakinesis, the 

 chromosomes get still shorter and there are found no more ring- 

 or X-shaped gemini. The paired chromosomes lie close to each 

 other and form dumb-bell-shaped gemini (Figs. 12, 13). The 

 further change of gemini does not proceed in equal pace among 

 themselves, so that the chromosomes or gemini are found in 

 different shapes. One may present a dumb-bell-shape, while 

 the other assumes a more or less square shape (Figs. 14, 15, 

 20). The formation of the spindle begins around the nucleus 

 (Fig. 12), and as soon as the nuclear membrane and the 

 nucleolus disappear, it assumes at first the tripolar (Fig. 14), 



