CHAPTER VI 

 ANIMALS 



i. Geographical Distribution of the Arrangements for Pollination, i. Orni- 

 thophilous Flowers. Fritz Miiller's aud Belt's discovery of humming-bird flowers. 

 Sun-birds as pollinators. Scott-Elliot's observations in South Africa. Ornithophily 

 in New Zealand. Feijoa, a plant with sweet petals. ii. Entomophilous Flowers. 

 Different pollinators in lowlands and in mountain ranges. Hermann Miiller's observa- 

 tions. Decrease of entomophily in arctic countries. Insular floras and their pollinators. 

 Long-tubed Lepidopteron- flowers characteristic of the tropics. Special adaptations. 

 Yucca and its pollination by moths. Species of Bulbophyllum near Singapore. 2. Plants 

 and Ants. i. Ants as cultivators of Fungi. Leaf-cutting ants in tropical America. 

 Their nests and fungus-beds. Other ants that cultivate fungi, ii. Myrmecophily. Belt's 

 discovery of myrmecophilous plants. Acacia cornigera and A. sphaerocephala. Cecropia 

 adenopus. Proof of the utility of ants as protectors of plants. Other plants with axial 

 habitations. Plants in which leaves produce the habitations. Extra-floral nectaries. 



The adaptations of plants to the animal kingdom form an extensive 

 and largely investigated domain of oecology ; the geographical and 

 topographical aspects of the question have been, however, only slightly 

 considered, although there can be no doubt, and it has been actually 

 proved in certain cases, that differences in the animal world cause differ- 

 ences in the plant world. In the matter of the pollinating mechanisms 

 and the relations between plants and ants a very promising start has 

 quite recently been made in the direction just mentioned. As regards 

 the mechanism for the dispersal of seed, a connexion between the 

 distribution of certain animals and plants has been affirmed in certain 

 individual cases, but the question of the relations of size, form, taste, 

 colour, and other properties of fruits, to the requirements of the animals 

 that feed on them has not yet been touched upon. The multifarious 

 protective means of plants against destruction by animals, so far as they 

 may characterize districts and their separate formations, have been at best 

 approached quite hypothetically, except in the case of ants ; and the 

 phenomena regarding them have hitherto only exceptionally formed the 

 subject of serious scientific inquiry. Stahl's admirable work on ' Plants 

 and Snails * ' will, it is hoped, stimulate further research, which, if attention 

 be paid to geographical questions, will certainly lead to valuable results. 



1 Pflanzen und Schnecken, Jena, 18SS. 



