CERTAIN SPECIES OF ASCLEPIADEE. 57 
base of the folioles, although it is apparently secreted in very 
small quantities. Like the other species already described it is 
destitute of scent. 
Cordylogyne. 
The pollen-masses are oblong and bend outwards. On removal 
the arms bend slightly in. Combinations take place between 
the glands and pollen-masses in the usual manner, viz. by the 
insertion of the arms in the furrows of the gland. The flowers 
are very extensively visited by some insects unknown to me. 
This concludes my present examination of the order; but 
although imperfect, my observations lead me to expect great 
results from future investigations, and that we shall find in the 
other subdivisions of the order, viz. the Tribes Periplocee, Seca- 
moree, and Stapeliee, as wonderful contrivances graduating into 
each other as in the different tribes of Orchids. 
In conclusion, I would remark that sufficient evidence has 
been obtained to show that insects extensively fertilize these 
plants, and that there appears to be an adaptation between the 
form and movements of the pollinia, the ale of the anthers, 
and the position and shape of the folioles and corolla. 
The secretion of nectar, and the powerful scent, so offensive in 
some, so sweet in others, are probably by no means the least im- 
portant functions of the plants. 
As a rule these plants are dull-coloured ; but there are many 
conspicuous exceptions among the Stapeliez and others. 
From the very small quantity of mature follicles produced in 
each plant, so disproportionate to the number of flowers, it is 
highly probable that these plants require to be impregnated by 
several pollen-masses ; and when we take into consideration how 
many pollen-masses are removed in proportion to those inserted, 
it would seem that in most species nature is less economical in 
her adaptation of means to ends than she is in most instances. 
It is also a singular fact that although all the flowers have two 
carpels, one is almost universally abortive. 
A general view of all these facts would lead to the conclusion 
that the adaptation of the several parts of the flower, in such 
Asclepiads as have been examined, is inferior in its perfection to 
that attained in Orchids. Perhaps some sort of compensation 
is obtained by the relatively large size of the seeds and the tufts 
of silken hair with which they are provided, by means of which 
they are wafted away by the slightest breeze. 
