72 INTRODUCTION 



As pollen is easily spoilt by moisture, provision is found for protecting it from 

 damp: e.g. the versatile anthers of grasses, &c., only open in dry air, so that the 

 probability of wetting is small. Among the pendulous catkins of alders, hazels, 

 birches, poplars, hornbeams, &c., the anthers are sheltered under shield-shaped 

 covering-leaves. According to Kerner ('Nat. Hist. PI.,' Eng. Ed. i, II, p. 148) the 

 pollen of the trees and bushes just named, after actual discharge from the anthers, is 

 not at once scattered through the air. It is at first heaped in some place in or near 

 the flower that is sheltered from moisture, and thence it is blown by the wind only 

 when the environmental conditions are most favourable for its distribution. In the 

 plants named, the dorsal side of the flowers serves as temporary storing-place for the 

 pollen; among the pines, firs, and spruces (op. cit., pp. 145-8) it is the excavated 

 dorsal side of the stamen immediately below ; in the case of the yew it is the shield- 

 shaped connective, just as in Juniperus, Cupressus, Thuja, Platanus. 



In Hippophae rhamnoides (op. cit., p. 148) the pollen is concealed in two 

 shell-like investing leaves that meet above, but are open at the sides. Among the 

 species of Potamogeton, the pollen falls during quiet weather into an excavation of 

 the flower-leaf situated below the anthers. In Triglochin the pollen falls, as I have 

 shown, into the crescentic or boat-shaped pockets that represent the perianth-leaves, 

 and which are situated under the anthers ; from these it is scattered even by the 

 lightest breeze ('Blumen und Insekten auf den nordfriesischen Inseln,' p. 136). 



Far more numerous and more interesting adaptations for the protection of 

 pollen than those possessed by anemophilous flowers are found among the more 

 highly developed entomophilous flowers, since shelter for their smaller quantity of 

 pollen is a pressing necessity. 



III. Animal-pollinated Plants, Zoidiophilae (Z). 

 {a) Plants with Bat-pollinated Flowers, Chiropterophilae (Ch). 



The first observed case of flowers pollinated by bats was described by W. Burck, 

 in the Annals of the Botanic Gardens at Buitenzorg (1892) — a Freycinetia (Panda- 

 naceae) that occurs in Java, and which climbs to the very highest parts of the tree 

 that supports it, develops several times a year a number of large flowers of a delicate 

 rose colour, which look very conspicuous among the long, dark-green leaves. Many 

 of the flowers are found lying on the ground, and from these it appears that the 

 plant is dioecious. In both male and female flowers the three inner-coloured 

 structures that play the part of petals are devoured by a bat, the Kalong, or 

 Flying-fox (Pteropus edulis). While this animal is eating these alluring structures 

 of the male Ibwer, it touches the pollen-covered anthers with its hairy head, and 

 when visiting a female flower transfers to the stigma the pollen thus received. Until 

 it is observed that the transference of pollen is otherwise effected, it must be assumed 

 that the apparent devastation which the Kalong effects among the flowers of the 

 Freycinetia serves the useful purpose of pollination, so that the plant must be 

 described as bat-pollinated. 



Plants that are pollinated by bats have also been observed in Trinidad. In 

 the Bulletin of Miscellaneous Information of the Royal Botanic Garden at Trinidad, 

 ii, part 3, No. 10 (April, 1897), pp. 30, 31, J. H. Hart, Superintendent of the 



