Origin of Sexuality 263 



protoplasm, is reestablished. Here gradual redistribution of 

 the chromatin material, along mth nucleoplasmic substance, 

 starts the formation of two daughter nuclei. 



The earlier phases then in division of most cells, both plant 

 and animal, that take place up to the point where splitting 

 lengthwise of each chromosome occurs, and which has been 

 designated the prophase and the metaphase, are scarcely if at 

 all represented in Spirogyra, and constitute an added complexity. 



It would be inappropriate here and now to follow many 

 details of division that cytologists have discussed. But, in 

 the light of what we already know of the process, cell division 

 in nucleate plants represents a segregation and selective sort- 

 ing out of molecular complexes of chromatin and protoplasm, 

 under the action of cognitic energy, that here shows positive 

 and negative polar effects, which exhibit themselves much as 

 in electric fields of action. Why these effects should be re- 

 garded as due to discharge of cognitic and not of electric energy 

 is discussed elsewhere (p. 130). 



But, in relation to the disruptive discharge of cognitic energy 

 from the chromatin substance, it may be that biotic energy, 

 as traversing the protoplasm, exerts a certain inhibiting or 

 restraining action, in relation to the centrifugal action of the 

 cognitic energy. 



Now in connection with cell division on the one hand, and 

 sex-cell formation on the other, it should be observed that 

 the more mmutely the continuous life history of the simpler 

 plants and animals is studied, the more exactly do we realize 

 that the process of division proceeds, under normal environ- 

 ment, to a strictly limited extent. Even in highly complex 

 plants and animals the same principle seems to hold, and is 

 associated with the terms maturity, senilitj^ decay, death. 

 If we confine attention to the simpler organisms meanwhile, 

 the species of Desmideae, of Zygnemete, of Oedogonieae, and 

 of Coleochaeteae, all show very definite, even though varying, 

 periods of cell division, and at equally definite but short i)eriods 

 sex-cell formation occurs. 



As examples the writer need only refer to his owti observa- 

 tions made on species of Spirogyra in the region round Pliila- 



