296 
H. F. Wernham. 
Cncurbitacece. There remains for consideration one family 
included in Engler’s Campanulatse, the Cucurbitaceae. This is a 
large group, including over 650 species of characteristic habit and 
facies, inhabiting tropical regions for the most part. These are 
chiefly annual herbs of rapid growth, climbing by means of tendrils, 
with palmately veined and lobed leaves ; and the relative constancy 
of this habit, together with the prevalent separation of the sexes 
in the flowers (they are rarely hermaphrodite), suggests that 
Cucurbitaceae are a specialized family, standing high and terminally 
upon their particular shoot of the evolutionary tree. 
The calyx and corolla, which are both regular, are respectively 
gamosepalous and gamopetalous, and the latter character affords 
the justification for including this family in Sympetalae, as in 
Engler’s system. In previous systems, notably those of Bentham 
and Hooker and of Warming, Cucurbitaceae have been classed with 
polypetalous groups, in spite of their prevailingly sympetalous 
corolla, for reasons which we shall endeavour to discuss presently. 
The andrcecium is of particular interest, and it affords the 
basis for the sub-division of the family. 1 The fundamental type of 
androecium consists of five stamens (i.e., isomerous with the 
corolla), each with a bilocular anther ; this condition characterizes 
the tribes Fevilleae, in which the filaments are free or almost free, 
and Sicyoideae, in which the filaments are united to form a column. 
These two tribes comprise, however, oidy about 20% of the total 
number of species in the family. In the majority of cases, together 
representing about 63% of the family, the androecium consists of 
three stamens—two with quadrilocular anthers, and one with a 
bilocular anther. The structure of the quadrilocular pair in the 
several forms is strongly suggestive of their origin by fusion in the 
course of descent 2 ; and this, according to Payer, 3 is borne out by 
the facts of the floral ontogeny. 
Taking the bilocular microsporangium, then, as a unit, the 
androecium in these apparently triandrous flowers typical of Cucur¬ 
bitaceae may he, in a phylogenetic sense, really pentamerous and 
isomerous with the corolla. The anther-sacs are variously elabo¬ 
rated in different forms as the result of elongation and curvature 
into S- and U- shapes, and the fusion is very diverse in degree, as 
1 According to Pax, in Engier, DieNatiirlichen Pflanzenfamilien, IV. 
5, p. 10. 
2 See the figures of various types of cucurbitaceous androecium 
in Engier, loc. cit., p. 5. 
3 7 vaiti (V Organoge'nie compared dc la Fleur , p. 441. 
