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THE AMERICAN NATURALIST [Vol. XLTV 



phytic in character. Allen found that when the fusion 

 nucleus made preparations for the first mitosis the chro- 

 matic material previously in the form of an irregular net- 

 work gathered at one side of the nucleus in the manner 

 characteristic of synapsis. There was evidence of a pair- 

 ing of the chromatic threads during the process of synap- 

 sis which is interpreted by this author as indicating a 

 pairing of the chromosomes from the two gamete nuclei. 

 Following synapsis the chromatic material becomes dis- 

 tributed as a coiled thread from which the chromosomes 

 are differentiated, that in a later stage are found scat- 

 tered through the nuclear cavity. A count of the chro- 

 mosomes at this stage indicated that the number thirty- 

 two is the double or diploid number for the species 

 studied. Some of the chromosomes were clearly as- 

 sociated in pairs, a condition that becomes more evi- 

 dent in later stages when at metaphase of the first 

 mitosis the now much condensed chromosomes are as- 

 sembled at the equatorial plate. In this mitosis the chro- 

 mosomes are short and thick, in sharp contrast to the* 

 long narrow bent rods which are characteristic of the 

 second mitosis. Allen then bases his conclusion that the 

 first mitosis in the oospore is a reduction division chiefly 



by a long resting period, and on peculiarities in the form 

 and grouping of the chromosomes, which peculiarities 

 are similar to those of the heterotypic division in hfgher 

 plants. 



It would seem then that Coleochate can no longer be 

 considered as a type very helpful in considerations, of the 

 origin of the sporophyte or suggestive of affinities with 

 the archegoniates. With respect to the latter point the 

 simple unicellular character of the sexual organs offers 

 further difficulties to a relationship to the archegoniates, 

 since the multicellular arehegonia and antheridia of this 

 last group apparently require an origin from a multicel- 

 lular type of sexual organ such as is best illustrated 



