I I 2 
H. F. Wernham. 
For the rest, the number of carpels varies, but 3 or 3m is a 
common number,—Fagales (3-2-6), Santalales (3-2-1), Aristolo- 
chiales (6-4-1), Polygonales (3), Centrospermse (3-1-5-00). 
Proceeding to group (b), a primitively indefinite number of 
carpels occurs prevailingly in Ranales, and in certain Rosales; the 
large numbers found among Parietales, Malvales, Myrtiflorae, and 
Opuntiales, may be, as in the case of the andrcecium, the result of 
chorisis. 
The condition G=C prevails in Rosales, and in Geraniales 
(groups A, B). 
The transition from G=C to G=2 is observable in a few 
Rosales, in groups C and F of Geraniales, in Rhamnales, and Thyme- 
laeales, G=3 being a common number. A tricarpellary ovary occurs 
frequently in Sapindales, in which cohort the carpels are rarely so 
many in number as the petals, although G=2 is not uncommon. 
Of the Umbelliflorae, the Araliaceas retain the arrangement 
G=C; but the remaining members of this cohort, including the 
large order Umbelliferae, have a bicarpellary gynaecium. 
It will be gathered from these statements that the gynaecium 
displays a development parallel with that of the andrcecium so far 
as numbers go, both in progressive oligomery and in secondary 
branching. The general tendency, moreover, is to a pistil of 2 
carpels, 3 being perhaps the number of most common occurrence 
in the Archichlamydeas ; this may very probably be the result 
largely of mechanical causes. 
In respect to fusion of the sporophylls, however, the evolutionary 
development of the gynaecium is far ahead of, and quite independent 
of, the development of the andrcecium. An apocarpous pistil is 
decidedly the exception in the Archichlamydeae, and is non-existent 
—primitively at any rate—in the Sympetalae. This is readily 
intelligible on the grounds of mechanical conditions of growth and 
economy of space, the female portion occupying the central position 
in the flower, and also in view of a general tendency, to be 
mentioned presently, to form a unilocular ovary, frequently 
containing a single ovule only. 
In group (a) syncarpy is the rule, with very rare exceptions, 
and the ovary is nearly always unilocular. 
Of group ( b) Ranales is the only cohort which is charac¬ 
terized by an apocarpous pistil, and true apocarpy is extremely 
rare in the other groups. It is found in the Rosales; while 
the transition to syncarpy is traceable in Geraniales, in which 
