614 The Milkweeds. [July 
“inability to cope with more vigorous forms of vegetation. Th 
the presence of the plant at a distance, while the spring-trap was 
a necessary contrivance to certainly secure the transferrence of 
the pollen from one’plant to another. 
sense. The species of the genus Hoya have climbing stems, ~ 
thick, succulent leaves, and clusters of waxy flowers. Hence 
the common name of wax-plant. Various species are cultivated, — 
and are great favorites because of their fragrance and beauty. 
It is stated that the young leaves are used by the natives O 
Ceylon in their curries; and one curious feature of the plant is 
that the flowers come from the same bud year after year. 
Fic. 8.—Flower of Hoya. S, naa D, disks a ER ge z 
of Pollinia, pendage; D, disk. ‘a 
‘The fertilization of hy globulosa possesses points of need a 
the mechanism being much the same as in Asclepias. It has 
been described in the Gardeners’ Chronicle for April 29, 1882, by 
Mr. W. G. Smith, as follows: The flowers are regular, grow in 
clusters, and are very fragrant. The pollen-grains are united in 
clusters and enclosed in pouches, five in number. The glutinous, 
dark-colored disks of the pollinia are the only parts of the sta- 
mens visible in an open flower. If an insect, attracted by the — 
“fragrance, alights on a flower, it almost invariably happens that 
- one foot slips and is caught by one of the sticky disks. Some 
