212 IP s t e I s i a 



unknown. In the light of further knowledge 

 of these forms, it has been necessary to greatly 

 modify the original definition of the groups, 

 while the distinctions between them have be- 

 come mucli more vague and indefinite than 

 they were formerly supposed to be. 



In the light of these facts, it has seemed 

 best to give Abies its wide significance, rec- 

 ognising as sections of this genus several groups 

 of plants which are currently considered genera. 

 Larix, Pseudolarix and possibly Cedrus also, 

 are regarded as small genera very closely allied 

 to Abies, but differing from it in a somewhat 

 more marked manner than the sections of Abies 

 differ from one another, while Pinits is a second 

 large and complicated genus clearly distinct 

 from Abies. 



