THE MONOCOTYLEDON THE UNIVERSAL TYPE OF SEEDS. 511 
that the cotyledons are not original and separate creations, but a 
divided unity. My next observations were on some acorns of 
Quercus agrifolia the division into cotyledons was numerous and 
irregular. Cut across vertically some representing the letter C, 
others the letter N, and again, with four cotyledons the letter M. 
Here again it was clear that whatever the form and number of the 
cotyledons there was no increase of the original cotyledon mass. 
Examining sprouting peach kernels, the variations in form and 
number were of the most remarkable character. I need not repeat 
them in detail here, as they are reported in the April and Ma 
“ Proceedings of the Academy of Natural Sciences of Philadel- 
phia.” In addition to the fact of no increase in the whole coty- 
ledon mass, it was here clear that when the cotyledons were dupli- 
cated, the duplications at least were subsequent to the original ones. 
Still so far nothing had been seen to indicate when the first pair 
of cotyledons were formed. Quercus macrocarpa and Quercus pa- 
lustris were silent to my questions. In a large number I found no 
variations whatever. Each mass was divided smoothly and ex- 
actly into two cotyledons. Quercus robur, the English oak, how- 
ever gave some curious evidence. Two germs under one seed 
coat were numerous and often three, and the cotyledons took on a 
variety of forms. But there was never any more increase in the 
cotyledonous mass, than if but two lobes had been formed and 
there was no more rule in the division than there would be in the 
sudden breakage of a piece of glass. A detailed account of these 
will also be found in the “ Proceedings of the Academy of Natu- 
ral Sciences of Philadelphia” for May. Quercus rubra, the Amer- 
ican red oak, furnished the one link wanting to connect the first 
division into lobes with the other phenomena. All the acorns ex- 
amined had three or four sutures on the cotyledon mass, and ex- 
tending all along the longitudinal surface externally, without 
any reference to cotyledonal divisions. These sutures extended 
sometimes but a line in depth, at others almost to the centre 
of the mass, always accompanied by the inner membrane, as is, 
the case in ruminated seeds. The whole mass was divided only 
in two parts in any that I examined of this species, but the 
division was always in the direction of the sutures. Hence each 
cotyledon was very irregular. Sometimes one-third the mass 
only went to one while the other had fwo-thirds of the whole 
mass. It was easier to burst in the weaker line of resistance. But 
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