PART IIT. | THE MECHANISMS OF FLOWERS. 425 
evening. In the daytime I have sometimes seen Halictus cylind- 
 ricus, K. 3, and Megachile centuncularis, L. g, and Hmpis and 
_ Rhingia in special numbers, all creeping into the base of the 
flower, and inserting their proboscides through the slits between 
- the filaments. Rhingia rostrata, L., applies its labelle fre- 
_ quently to the anthers, stigma, and inner wall of the corolla, 
apparently picking up scattered pollen. Meligethes, Thrips, and 
minute Podure also frequent the flowers during the day. 
Delpino mentions Sphinx convolvuli as a fertiliser of C. sepium 
(172, 352); he tells me by letter that one of his friends catches 
this insect in numbers, standing by a hedge overgrown with the 
plant, holding thumb and forefinger over a flower and closing its 
orifice when the insect has entered ! 
In England, where Sphinx convolvuli is rare, C. sepiwm seldom 
produces seed ; in Scotland, where S. convolvuli seems not to occur, 
C. sepium is rarely found wild (773). In the north of Ireland, 
according to Mr. T. H. Corry, C. sepiwm is far commoner than 
C. arvensis, and Sphinx convolvuli is comparatively frequent. 
| Cuscuta Epithymum, L., is homogamous. Honey is secreted 
_ by the lower part of the ovary, and is sheltered by scale-like 
appendages of the corolla. The flowers are visited by Sphegide, 
and in absence of insects fertilise themselves (590, III.). 
Cuscuta, according to Kuhn, has cleistogamic flowers (399). 
Ipomea pestigridis, L., has cleistogamic flowers, which were 
known to Dillenius. 
Calonyction, Chois.—The flowers are sterile to their own pollen. 
Orv. SOLANACEZ. 
312. SOLANUM TUBEROSUM, L.—The peduncles stand almost 
horizontal at the time of flowering, and the five-pointed rotate 
limb of the corolla becomes nearly vertical. Five anthers meeting 
to form a cone project from the flower and surround the style, 
which protrudes beyond them and curves more or less downwards 
at its stigmatic end. All the stamens bend very slightly down- 
wards, and the lower anthers project somewhat in advance of the 
others. The anthers begin to dehisce at their apex, and when 
touched allow a little pollen to fall out; in some which I ex- 
amined a large quantity of pollen-grains (from ‘013 to ‘(021 mm, 
in diameter) remained in a shrivelled condition. 
i Since the flower secretes no honey and affords little pollen, it 
i is very scantily visited by insects, In spite of repeated watching, 
