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1903] BEHAVIOR OF THE CHROMOSOMES 269 



the second longitudinal splitting be discerned before metakinesis. 

 As soon as the daughter chromosomes separate, howev^er, each is 

 seen to consist of two similar granddaughter segments. The 

 figures which these pairs of segments present will depend/ of 

 course, upon the orientation of the daughter chromosomes toward 

 each other, their shape, and mode of attachment to the spindle 

 fibers. 



The retreating segments, therefore, may form V's, U's, or 

 more or less contiguous rods, which may be undulating or 

 abruptly bent, and, as is sometimes the case, hooked at the ends 

 directed towards the poles {fig. 41) . 



Having reached the poles, the granddaughter segments do 

 not, at least as far as my observations have extended, form 

 immediately a regular spirem of a uniform thickness, but there 

 is here a greater tendency on the part of the chromatin elements 

 to become reticulated and pass into a structure closely approach- 

 ing that of a resting nucleus. This was found to be true in, all 

 cases observed. As will be seen from fig. 42, the two daughter 

 nuclei present a structure which is certainly very near that of a 

 resting nucleus. Several nucleoli are present, and there is no 

 regular, continuous spirem. Although the nuclear thread may be 

 continuous, yet the chromatin is in the form of granules that are 

 of a very variable size and unevenly distributed. Certain por- 

 tions of the nuclear thread contain apparently a single row of 

 small chromatin granules, as in an early prophase of karyokine- 

 SIS ; in other portions two rows of these granules are present, 

 while still other parts are thicker and somewhat lumpy. 



In the light of all the facts observed, nothing seems more 

 certain than that in the daughter nuclei all identity of the chro- 

 mosomes is lost from observation. While it is true that a greater 

 pause intervenes or seems to exist between succeeding nuclear 

 divisions than between the first and second mitoses, yet it does 

 not follow that the second division takes place immediately after 

 the first without a resting pause. 



As regards the details of further karyokinetic activity in the 

 embryo-sac, I am able to add little to my former observations. 

 As already mentioned (Mottier, '98), the second mitosis bears 



