194 The Science of Life. 



tion of flowers by insects; the problem of galls; the 

 symbiosis of Algae and Radiolarians ; and a hundred 

 other inter-relations. A convenient introduction to the 

 subject will be found in the writer's Study of Animal 

 Life and in Prof. Geddes's Chapters in Modern Botany. 



It is again to Darwin that we are most indebted for 

 our realization of the now familiar biological fact that 

 inter-reia- no an i ma l lives or dies to itself. We refer 

 tions among to such facts as the following : the existence 

 of quaint partnerships, as of crocodile and 

 crocodile-bird; the closer " commensalism " illustrated 

 by certain hermit-crabs and their companion sea-ane- 

 mones ; the frequent occurrence of parasitism ; the estab- 

 lishment of complex domestic and social relations ; and 

 the manifold adaptations which may be called "shifts 

 for a living ", such as mimicry and masking. 



As a particular example we may refer to the investi- 

 gations of Dr. Wasmanri, M. Charles Janet, and others 

 on the "myrmecophilous" animals, e.g. small beetles, 

 which live along with ants, and in their varied relations 

 present a close parallel to the animals found in a human 

 dwelling; some are distinctly unwelcome, others are 

 simply tolerated, some are useful, others are mere 

 "pets". 



The modern recognition of the fundamental physio- 

 logical resemblances between plants and animals was 

 inter-reia- a momentous step in the history of biology; 

 tions among the recognition of their bionomical resem- 

 blances is hardly less important. The struggle 

 for existence between plants in the tropical forest or 

 in the hedgerow; the many degrees of parasitism of 

 plant upon plant; the living together or symbiosis 

 which is illustrated in the combination of Alga and 

 Fungus to form a Lichen, and so on, are instances of 

 inter-relations among plants which have their parallels 

 in animal life. 



If we study Kerner's Life of Plants, or Wiesner's 

 Biologic der Pflanzen, or a similar work by Ludwig ; if 

 we read Rodway's account of death in the tropical forest 

 or Gardiner's sketch of the struggle for existence in a 

 meadow; if we consult Schimper on myrmecophilous 



