ENDOMIXIS 



657 



greed animals from day to day, as emphasized by Woodruff and Erd- 

 mann (1914, pp. 457-72) and Beers (1935). 



The study of pedigreed series of animals, for example, precluded, it 

 is believed, the possibility of "combining stages of hemixis and autogamy 

 in one scheme." Indeed, Erdmann and Woodruff (1916), contrasting 

 endomixis in P. caudatum and P. aurelia, stated that they had "some 

 data which suggest that under certain conditions merely a partial re- 

 organization, not involving the formation of macronuclear Anlagen, 



Figure 162. Climax of 

 endomixis in Paramecium 

 aurelia. The old macronu- 

 cleus is merely in the form 

 of a membrane from which 

 the numerous chromatin 

 bodies have been ejected 

 and are free in the cyto- 

 plasm. Eight so-called re- 

 duction micronuclei. (From 

 Woodruff and Erdmann, 

 1914, plate 2.) 



may lead, at least temporarily, to the continuance of the life of the line." 

 This would appear to be Diller's "hemixis." 



On the other hand, "overlooking the maturation and synkaryon 

 stages" is a different matter, as will be appreciated by anyone who has 

 worked on the cytology of Paramecium. This may have occurred, even 

 though Woodruff and Erdmann naturally "expected" to find autogamy 

 when they observed the primordia of macronuclei in non-conjugants. 

 Their inability to find maturation spindles and synkaryon of course led 

 them to coin the name endomixis for the process. But an equally plausible 

 explanation, at least in the mind of the writer, as to why these investi- 

 gators did not find such stages, nor even the paroral lobe, in which the 

 synkaryon is characteristically located, according to Diller, is that these 



