THE EVOLUTION OF PLANTS 



(187s) lield the opposite opinion. Hill and de Fraine 

 (1908-1910) are among the recent protagonists for the 

 hypothesis that dicotyledons are the more primitive. One 

 of the most recent studies is that by Bucholz^ who ex- 



J G 



Fig. 104. — Development of stem tip and cotyledons in Pinus Bank- 

 siana. Dotted line represents plerome of root-tip; shaded area, meristem 

 of stem tip; E, I, J, K, fusing cotyledons. (After Bucholz.) 



amined the embryos of pine, spruce, larch, juniper, balsam 

 fir, cedar of Lebanon, and others. Many instances of 

 the fusion of the primordia of cotyledons were found, but 

 no evidence of cotyledonary splitting. This fusion has 

 resulted in reducing the number of cotyledons, and, in 



' Bucholz, John T. Studies concerning the evolutionary status of poly- 

 cotyledony. Am. Journ. Bot. 6 : 106-119. March, 1919. 



