NA TURE 



6ii 



THURSDAY, FEBRUARY 4, 1915. 



THE WEB OF LIFE. 

 Tierbau und Tierlcben in ihrem Ziisammenhang 

 betrachtet. By Prof. Dr. F. Hesse and Prof. 

 Dr. F. Doflein. Band ii. Das Tier als Glied 

 des Xaturganzen. By Franz Doflein. Pp. xv + 

 960 + plates. (Leipzig- and Berlin: B. G. Teub- 

 ner, 1914.) Price 20 marks. 



ONE of the fundamental ideas of biology, 

 which found many illustrations in the 

 work of Darwin, is that of the inter- relatedness of 

 org-anisms in the web of life. Just as there is a 

 correlation of org^ans in the body, so there is a 

 correlation of organisms in the economy of nature. 

 No creature lives or dies to itself ; the orbit of 

 one life influences many others; everywhere we 

 find linkages and wheels within wheels. An 

 organism is compared by Prof. Doflein to a 

 modern house, connected by various pipes and 

 wires with other houses in the city and with the 

 outer world, but the image is crude and too 

 static. It is only in man's personal affairs 

 that we find anything like the manifold, 

 intricate, and subtle inter-relations that are to 

 be seen in vigorous animals leading a full life. 

 It is, indeed, altogether a matter of action and 

 reaction between organism and environment, but 

 with what complexity and nuance ! Now things 

 are in the saddle coercing the organism, and 

 again the living creature exercises its prerogative 

 and becomes master of its fate. 



Prof. Doflein, Weismann's successor at Frei- 

 burg, has been studying this aspect of animal 

 biology for more than ten years, and has given 

 us his results in a work which must be placed 

 in the front rank among ecological or bionomic 

 studies. The book is nothing short of a great 

 achievement. It has gathered interesting material 

 from many fields ; it includes much that is per- 

 sonal ; it has worked out a clear classification of 

 the manifold inter-relations ; it is written in a 

 vivid style ; and if we said all we think about the 

 abundance, freshness, and beauty of the illustra- 

 tions, we should not be believed. We do not 

 know of any British, American, or Frenc^i book 

 of natural history that even approaches it — a fact 

 doubtless implying a smaller purchasing public. 

 Prof. Doflein is well known for his work on the 

 Protozoa and as a naturalist-traveller, and it is 

 remarkable that he should have found time during 

 the last ten years to write this large volume, a 

 fit companion to its predecessor, by Prof. Hesse 

 of Bonn, which treated of the organism as an 

 individual. 



In dealing with the comprehensive subject of 

 NO. 2362, VOL. 94] 



the inter-relations of animals in the web of life. 

 Prof. Doflein has evidently had in his mind 

 throughout two allied, but distinct, general con- 

 ceptions. The first is that of the organism as a 

 bundle of adaptations to normal circum.stances — 

 what he calls " organisatorische Anpassungen " ; 

 the second is that of the organism as a self- 

 assertive plastic agent, which can adjust itself to 

 environmental vicissitudes — what he calls "regu- 

 latorische Anpassungen." The first is the here- 

 ditary racial equipment of wrought-out adapta- 

 tions (as far as these concern give-and-take with 

 animate and inanimate surroundings); the second 

 is the individual capacity for adjustment, for 

 modification, for thrusting as well as parr\ing. 

 In both cases the adaptiveness may be structural, 

 or functional, or psychical. Thus a ptarmigan 

 from the mountains has a stronger heart than a 

 willow-grouse from the plains — a structural adap- 

 tation. A bird or mammal continuously and nor- 

 mally regulates its production of heat according 

 to its loss — a functional adaptation. Ants have 

 art instinctive behaviour in relation to their queens 

 — a psychical adaptation. But when a mammal 

 transported to a cold country puts on a thicker 

 coat, or when a bird adjusts the nature of its food- 

 canal to altered diet, or when ants taken from 

 Algiers to Switzerland entirely alter the door of 

 the nest (in relation to new enemies), we have to 

 deal with structural, functional, and psychical 

 adjustments which are not more than individual 

 reactions. This distinction between racial adapta- 

 tion and individual adjustment is prominent in the 

 book, but the author does not use it stiflSy. He 

 is clear, for instance, that the individual trades 

 with his talents. 



Beginning with the animate environment, Prof. 

 Doflein deals with nutritive relations (including 

 symbiosis, commensalism, parasitism, etc.); rela- 

 tions to enemies (including protective resemblance, 

 mimicry, autotomy, etc.); sex-relations; migra- 

 tions; care of offspring; social relations (including 

 gregariousness, co-operation, and the communi- 

 ties of ants, bees, and termites). After 750 pages 

 on these attractive themes, he passes to the 

 inanimate environment, and deals with cosmic 

 periodicities, the medium, the substratum, pres- 

 sures, chemical influences, the quantity and quality 

 of the food, temperature, climate, and light. This 

 part of the book is like Semj>er's well-known 

 work, "The Natural Conditions of Existence as 

 they affect Animal Life" (1881), brought up to 

 date. The volume ends with a discussion of the 

 theoretical significance of adaptive structures 

 and habits. \Vhat is new is the synthetic treat- 

 ment of the whole question of inter-relatedness, 

 which is, of course, fundamental in any biology 



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