82 



MORPHOLOGY OF ANGIOSPERMS 



The Number of Chromosomes Continued 



It is evident from the table that Strasburger and Guignard 

 were pioneers in this work and that they still remain the most 

 active contributors. It is of interest to note that when atten- 

 tion was first directed to this subject, the number of chromo- 

 somes reported for the sporophyte, while exceeding that of the 

 gametophyte, was not precisely twice that number. The sub- 

 ject is one of great difficulty, and doubtless the countings of 

 competent investigators have often been influenced by their 

 theories, while their followers have been content too often with 

 confirming a reported number. Variations from the character- 

 istic number are numerous. In the gametophyte the number 

 of chromosomes in the antipodals is frequently irregular, with 

 a tendency to higher numbers ; but an explanation may be found 

 in the irregular nuclear divisions which present some of the 

 characters of amitosis (Miss Sargant 41 ). Variations are even 

 more frequent in the sporophyte, but it is well known that 

 mitoses are frequently irregular, and it is easy to imagine that 

 a chromosome may fail to split or that an unequal distribu- 



* Parthenogenetic. 



f More than 16, probably 24, in endosperm. 



