24 THE AMERICAN NATURALIST. (VoL. XXXIX. 
conditions imposed by the seeds. Might not these same causes, 
whose effect on two cotyledons is so often apparent, have pri- 
marily induced the division of a single cotyledon into two? In 
considering divided cotyledons, Lubbock ('92), concludes that 
the bifurcation of the cotyledons in such plants as Eschscholtzia 
and Schizopetalon are adaptations whereby the cotyledons are 
better able to free themselves from the seed. If for this pur- 
pose four cotyledons are superior to two, in what far greater 
proportion are two cotyledons superior to one? 
Although its evidence can never be taken as absolute, still we 
are justified in placing some value on recapitulatory development. 
If the monocotylous condition arose through the union of two 
cotyledons we might reasonably expect to find, in our transition- 
types, that two distinct cotyledon-primordia would first appear, 
and conjoint development occur later. Such a sequence we 
actually find in the development of gamophyllous perianths. 
But in all the anomalous forms cited by Miss Sargant, of which 
the embryogeny has been studied, a single primordium first 
appears which, if the cotyledon is to become lobed at all, later 
bifurcates. 
In her first paper on this subject, Miss Sargant (: 02) attrib- 
uted the reduction of the cotyledons to their specialization as a 
sucking organ. Of the monocotyledons, she writes, *I have 
regarded them for some time as specialized forms of an ancestor 
with two seed-leaves. The complete union of the cotyledons 
may very possibly be due to their common specilization as a 
sucking organ. It is true that all cotyledons begin life by 
absorbing nourishment from a food-body within the seed, but in 
dicotyledonous seedlings they commonly lay aside that function 
at an early period, even though they may never become assimi- 
lating organs. Among Monocotyledons on the contrary, the 
apex of the cotyledon often remains within the endosperm 
throughout the existence of both, a period which covers years in 
palms and some other plants. Such a habit as this would natur- 
ally lead in course of time to the fusion of the cotyledons within 
the seed." This hypothesis would seem to maintain that the 
specialization in seeds has been from the exalbuminous towards 
the albuminous condition. This supposition however meets 
