1902] BRIEFER ARTICLES ae 
up to the larger ones of the full-grown individual. Keeping in mind 
the fact that with the gradual change and increase in complexity of 
the adult in phylogeny, the representation of past adult stages is 
pushed further and further back in the ontogeny of the plant, one does 
not find it at all difficult to carry the idea a single step onward, and to 
consider the changes in cotyledonar form as influenced by this accel- 
ération in development. Lubbock states that the lobing is perhaps 
deeper in £. cicutarium than in the other species, which are also less 
lobed or pinnatifid in the adult. As regards the extra lobing in coty- 
ledons of &. cicutartum, therefore, I am inclined to adopt the view that 
acceleration in development supplies the most plausible reason, and to 
recognize the possibility of accounting thereby for the two constant 
lobes as well 
That lobation may take place for the sake of compact folding 
_ Seems, however, fully to be demonstrated by the other seedling with 
which Iam to deal. The genus Amsinckia has deeply parted cotyledons 
a (Ag. 7), but the following leaves throughout the life of the plant are 
simple, lanceolate, and entire. Hence it is equally possible that in 
£. dicutarium such lobes as areof a constant nature may likewise be 
. due to this cause, as argued by Lubbock. Researches upon the seed- 
ie lings of simpler leaved species of Erodium would give interesting evi- 
~ dence upon this point. a 
as Far more instructive seems the phylogeny of the trichomes in these ~ 
'wO Seedlings, both of which possess hairy cotyledons. The fact that 
- both Geran 
S.1s 
an in their phylogeny. The same is also true of the 
‘es laceae and Boragineae are characterized so generally | by - : 
: ees M itself significant as pointing out the early appear- 
laceae, where hairy cotyledons are likewise of frequent 2 
_ Acceptin 
be 
§ the views expounded by many writers, among © a 
mentioned Schaffer? and Jackson? as dealing withthe = 
“present close, wre Wuestion, viz., that the early leaves of seedlings : 
“Ueber die Very 
8s in the development of plants and animals. Mem. Boston 
89-153. 10 pls, 1899, ee ee 
