94 THE BROAD-SCLEROPHYLL VEGETATION OF CALIFORNIA. 



that a leptophyll, if of the common elliptic form, will be about 9 mm. 

 or less in length, and that the upper length limits of the next three 

 classes, assuming the same leaf -form, will be approximately 27 mm., 

 81 mm., and 243 mm. The sizes of the leaves were determined by a 

 study of the specimens in the herbarium of the University of Minne- 

 sota, which has an excellent representation of the Californian flora. 

 To provide for cases in which a species overlaps two classes, three 



LN 



N 

 Total 



NMi 



Mi 



MiMe Me 



Climax Chaparral 



Conifer Forest Chaparral 



Broad-sclerophyll Forest 



Fig. 21. — Leaf size in the broad-sclerophyll communi- 

 ties. See text. 



intermediate categories were made. Because such a large number 

 were found to cluster around the division-lines, it was thought best 

 to include also in the intermediate classes those which were con- 

 sistently very close to the limit, though not actually crossing it, so 

 far as was shown by the specimens examined. 



Figure 21 gives the results of the study. The generally small size 

 of leaf is manifest, all but 1 1 of the 74 species falling within the three 

 lowest classes — leptophylls, nanophylls, and microphylls. Further- 



