INVESTIGATIONS ON THE PHYLOGENY OF THE 



ANGIOSPERMS 



NO. 2. ANATOMICAL EVIDENCES OF REDUCTION IN CERTAIN 



OF THE AMENTIFERAE 



Irving W. Bailey and Edmund W. Sinnott 



(with plates iii-v and three figures) 



The earlier taxonomists by systematic studies, principally of 

 external characters, have contributed much toward a truly natural 

 classification of the angiosperms, but the problem is such an intricate 

 one that in searching for a satisfactory solution evidence from all 

 fields of botanical research must be considered and harmonized. 



In view of 



plants, the r 

 in regard to 



lven by com] 

 gymnosperms 



anatomists 



1 



lesis of Professor Jeffrey 

 ment of "aggregate " "a 



"multiseriate" rays in dicotyledonous angiosperms, merits careiu* 

 consideration by taxonomists, since, if shown to rest on secure 

 foundations, it is likely to produce radical changes in existing 

 systems of classification. 



The "aggregate" ray hypothesis 



The salient features of this hypothesis may be summarized as 

 follows: The angiosperms have not been derived from the Bennetti- 

 tales, but from ancestors which possessed only linear or uniseriate 

 rays, such as are a well developed feature of the Coniferales. During 



the warmer 



from 



number of seasons. The influence 



demand 



descending 



these earlier angiosperms. These "foliar" rays have persisted 

 in their very primitive "aggregate" condition (composed of con- 

 geries of small rays), and in their more advanced "compound 



condition (completely 



Botanical Gazette, vol. 58] 



families 



[36 



