PHENOMENA ACCOMPANYING FERTILIZATION 297 



somes in Paramecium aurelia, basing his view not on the chromo- 

 somes but on the number of fibers which he could distinguish in 

 the connecting strand between the two daughter nuclei. Later 



w* 





Fig. 147. — Paramecium caudatum; A, B, C, stages in the first meiotic division 

 during conjugation; A, shortening of the crescent and formation of pole-plate on 

 upper side; D, prophase of second meiotic division. (After Calkins and Cull.) 



observers have found that the number in all species of Paramecium 

 is much greater than this, running up to more than one hundred. 

 Dehorne (1920), on the other hand, finds no chromosomes at all, 



