148 THE POLLINATION OF SATYRIUM BI CALLOSUM, THUNB. 
He also records 1 that Disa graminifolia bears seed regularly, and concludes 
that it must be visited by insects, although after many years’ observation, he 
has only noticed the visits of two insects; one a fly, Pagonia angulata, and the 
other a small butterfly, Lycaena asteris. In the case of Disaferruginea, Marloth 2 
states that the flowers are regularly visited by the butterfly Meneris. Finally, 
for Satyrium coriifolium, Marloth 3 figures a bee, Lasioprosopa bigoti, Macq., 
as the visitor, although no mention is made of this insect in the text. Weale 4 , 
who observed Lepidoptera with pollinia attached, says: “In the spring of 1865, 
near the Koonap river, I caught several specimens of the smaller variety of 
Pieris gidica, and likewise of Pieris charina, With pollinia of some unknown 
species of orchid loosely attached to the sternum. On searching the neighbour- 
hood, a new species of Bonatea (B. Darwinii ) was discovered.” The stigmatic 
surfaces were seen to be thickly covered with pollen, and the flowers, which 
secrete honey abundantly, were observed to be frequently visited by insects. 
In the other papers dealing with pollination, the actual pollinating insect 
was not observed. Trimen 5 described the structure of the flower of Bonatea 
speciosa, from plants procured at Knysna, but grown in a conservatory in Cape- 
town. He says: “I am unable to supply any details as to the extent to which 
insect fertilisation is effected in this orchid, having had no opportunity of 
observing the plant in its natural localities.” 
Weale 6 describes the structure of a species of Disperis , in which he suggests 
that the tarsi of insects cause the removal and transport of the pollinia, as 
in the case of Asclepiadaceae. The orchid concerned produces numerous fertile 
capsules, but insect visits are not recorded. There is a note to this paper to 
the effect that this and two other papers sent to the Linnean Society were 
accompanied by drawings. These drawings were not published, and the 
Secretary of the Linnean Society informs me that the drawings are not now 
available. Weale does not state the specific name of the Disperis he examined, 
and without the drawings, the account is of little value. In another paper 7 , 
he mentions that in Disa macrantha, the flowers are of a bright colour, with 
strong scent, and of conspicuous size, though he did not observe insect visits 
or insects with pollinia attached. He suggests that insect visits occur, as the 
plant, bears an abundance of seed, but he also observed that self-pollination 
was very frequent. He says: “A jerk will detach pollinia and bring them into 
contact with the stigma. This in nature is not unseldom the case, as I have 
repeatedly found many flowers thus fertilised.” 
In a following paper, Weale 8 gives some notes upon some South African 
species of Habenaria. He says: “The plant does not appear to be visited by 
diurnal insects, but must be very attractive to nocturnal ones, as, although 
1 Marloth, 1915, p. 59. - Id. p. 189. 3 Id. Plate 56, C 7. 
4 Weale, 1869. 5 Trimen, 1867. 8 Weale, 1873, pp. 42-45. 
7 Id. pp. 45-47. 8 Id. pp. 47-48. 
