THE NATURAL HISTORY OF THE FLOWER. 293 
place it upon the stigma in other flowers, the entrance to the 
honey being very narrow. In the later stage of the flower 
autogamy will almost certainly occur, whether it be visited by 
insects or not. The distance between anthers and stigmas is 
extremely small, and a very slight displacement, such as might 
be caused by an insect grasping the corolla, will bring them into 
contact with one another. In the final withering of the flower, 
the corolla collapses over the stigmas, and autogamy may occur 
then. Aphides are common in the flowers; one of them was 
observed in the act of producing autogamy. It became stuck to 
the stigma in climbing out of the flower, and in its struggles 
almost emptied the neighbouring anthers of their pollen, which 
it brought upon the sticky stigmas. 
The pollen is smooth, but not, apparently, powdery, so that 
the mechanism cannot be compared with that of Erica or Galan- 
thus. Although the flower is pendulous, the pollen is often 
wetted by rain getting in; the water collects in a large drop at 
the mouth of the corolla, and then gets inside very easily. After 
a heavy shower, many flowers were found full of water. 
The flower is thus protandrous, with well-marked self-fertiliza- 
tion. All the flowers examined had set a full complement of 
seed. The only insect visitor observed beyond the Aphides 
above mentioned was Thrips, but only a few racemes could be 
watched, as there was but little material. Some stalks were 
found bearing male flowers only at the top of the raceme ; these 
had small shrivelled carpels. The plant may thus be andro- 
monecious under certain circumstances. One plant bore, in the 
middle of the raceme, about twenty flowers with all their organs 
aborted except the calyx. 
Hydrolea spinosa, Linv.—This plant belongs to the same 
family as Phacelia *, and its mechanism is somewhat similar. 
The flowers are in loose cymes, and azure blue in colour, with no 
perceptible scent. The stems, leaves, and calyces are covered 
with glandular hairs. The corolla is rotate-campanulate, 13 mm. 
across and 10 mm. in depth, the segments long, the tube short and 
wide. The five stamens are exserted, and bear versatile anthers 
with a large connective. Each lobe dehisces by a longitudinal slit, 
but does not at once turn completely inside out as in Phacelia. 
The pollen is brown. Honey is secreted by a disc below the ovary, 
and protected, asin Phacelia, by processes of the stamens. These 
are thick and fleshy, covered with stout papillx, and block up 
* Cf, antea, p. 53. 
