76 



This coupaa''ison serves to emphasize one xoiJ^t. rartic- 

 ulai'ly. At a critical stage an the life history of rather 

 closely related members ( Polysii<honia and Griffiths i a) of 

 a liighlj^ specialized ci'oup, the cytological ihenomena are 

 of a most varied nature. Turing the jieriod of synapsis 

 and up to the time of the formation of the cliromosomes, 

 the cytological events in Pol3''sii)}.onia are far more like 

 those in Liliim than those in Griff ithsia or Corall ina. 

 The behavior of the nucleus in tlie foz-mation of the tetra- 

 spores in Graffithsia is much more similair to that in Cor - 

 ailina than to that in Poly siphonia, a more nearly relented 

 genus. The bearing of these facts is obvious; cytological 

 phenomena cannot be considered trustworthy guides to rela- 

 tionships . 



