20 



VARIATION AND DIFFERENTATION IN CERATOPHYLLUM. 



lish Flora, I)." From this one must conclude that Schleiden either did 

 not count any considerable number of whorls, or else that he was dealing 

 with a highly differentiated local race. Judged by our data "Smith" 

 did not come far from the ''Kegel " by placing it at 8. Klercker ('85), 

 in his frequently quoted paper on the anatomy and embryology of 



Table 2. — Constants of variation in number of leaves per whorl for all unmutilated 

 whorls, without reference to position on the plant. 



»In Series V the constants for the very small plants (plants 2, 3, 4, 5, and 6) are not separately 

 tabulated. 



Ceratophyllum, has the following to say regarding the number of leaves 

 in the whorl (loc. cit., p. 8): "Le nombre [i. e., of leaves] dans chaque 

 verticelle en est en general constant sur le meme axe, mais varie avec 

 les axes. J'en ai trouve 7-12. ' ' This range agrees fairly well with what 

 we have found, though starting higher. It is in all probability, however, 

 a general estimate rather than the result of any extensive counting. 



