IP 6 t e I s i a 209 



It is to be noted that no section is incom- 

 plete internal agreement, even Hesperopeuce 

 which is monotypic, varying in the position of 

 the cones in different individuals. 



Tsuga and Pseiidotsuga are both small and 

 uniform groups of species, but Tsuga shows con- 

 siderable variety in the vascular bundle of the 

 leaf, and in Pseiidotsuga the leaf insertion, 

 which has long been considered a very important 

 character taxonomically, varies greatly even in 

 the same species, so that in this respect, some 

 specimens of Abies (Pseiidotsuga) taxifolia agree 

 with Tsuga, and others with Eu- Abies. 



Picea shows great variation in the shape and 

 structure of the leaf, but is otherwise very un- 

 iform, while Eu- Abies which likewise has great 

 variation in leaf form, shows also considerable 

 variation in the staminate flower, and in the 

 relative length of the scales and bracts of the 



constant one, such as the terminal cones of Tsuga with the terminal 

 or axillary cones of some species of Picea, is counted as one half 

 agreement. When, however, some individuals of a species differ 

 from others, as different individuals of Abies mertensiana differ in 

 the position of the cones, it is considered an occasional complete 

 agreement, and is reckoned as o-i. 



