Febbuabt 25, 1910] 



SCIENCE 



303 



zones in the Rocky Mountains, it would seem 

 that the latter might be expected to have twice 

 as many species. Switzerland has, of course, 

 been more thoroughly investigated, but the 

 large number of species given is not due to the 

 inclusion of the " critical " forms, for the au- 

 thors tell us in the preface that these are all 

 to be given separately in a subsequent volume, 

 the "Flore Critique." In the 1909 volume 

 the species are supposed to be such in the ordi- 

 nary sense, and a special mark is appended to 

 those (and they are very numerous) of which 

 segregates are known, the account of these 

 being promised in the later work. 



There is no doubt that the separation of the 

 ordinary from the "critical " flora, after the 

 manner of Schinz and Keller, is convenient 

 to the numerous class of botanists who are not 

 specialists in taxonomy. Professor Nelson's 

 work corresponds to the Swiss volume before 

 me while Dr. Eydberg's book on the plants of 

 the same region, expected in about a year, will 

 really be a " Flore Critique," at least to a con- 

 siderable extent. American workers are at 

 present roughly divided into two groups, of 

 which a modern European botanist would say 

 that one failed to discriminate the lesser 

 types, many of which are of the highest inter- 

 est from a biological standpoint, while the 

 other, recognizing minor segregates, treated 

 them all as species, without any attempt to 

 indicate in the nomenclature their various 

 kinds and degrees of relationship to the 

 species of the older school. We venture to 

 hope and believe that at length a middle 

 ground will be found in a system of classifica- 

 tion more like that of advanced European 

 workers, which permits the presentation of the 

 most minute details, without seriously dis- 

 turbing the current conception of species. 



T. D. A. COCKEEELL 



Umweli und Innenivelt der Tiere. Von J. 



VON IJEXKiJLL, Dr. med. hon. c. Berlin. 



Verlag von Julius Springer. 1909. 8vo, 



pp. 259. 



The bold and original investigations of von 

 TJexkiill have culminated in his " Umwelt und 

 Innenwelt der Tiere " ; culminated, not because 

 there are reasons to suppose that this will be 



his last contribution to science, or perhaps 

 even his best, but because he has synthesized 

 into a coherent whole the results of earlier 

 work, and with the addition of fresh materials, 

 and maturer judgments, has sketched in the 

 outlines of a reformed biology. 



Large sections of the book must be left to 

 those who have made certain protozoa, ccelen- 

 terates, annelids, molluscs, crustaceans and 

 insects, subjects of prolonged study, yet as a 

 whole, the work should appeal to every biol- 

 ogist, no matter what group of animals or 

 facts he knows best. It is these matters of 

 general appeal that concern us. 



First of all, a living thing is neither a 

 bundle of anatomical details nor a collection 

 of physiological processes, nor both of these 

 together, for things that live, live in an en- 

 vironment. To cultivate either anatomy or 

 physiology exclusively is as futile as the study 

 of environments with all the animals left out, 

 for the business of the biologist is to know, 

 not merely structure or function, but what the 

 vital machinery is, how it works and the cir- 

 cumstances under which the work is done. 



The organism, von TJexkiill teaches, must be 

 studied, not as a congeries of anatomical or 

 physiological abstractions, but as a piece of 

 machinery, at work among external condi- 

 tions. Our analyses, so far, have been by no 

 means exhaustive, for we have largely neg- 

 lected the fact that the organism makes its 

 surroundings. It is true that environment 

 includes the sum total of everything outside 

 the individual, and, within these limits, is the 

 same for all living things. Yet this is wholly 

 misleading, for environment is both essential 

 and unessential, and only the former counts 

 practically in the shaping of biological des- 

 tinies. The shark, the jellyfish and the plu- 

 teus, that swim side by side at the base of a 

 wharf-pile, under uniform conditions of sa- 

 linity, temperature, light and mechanical agi- 

 tation, have each a different effective environ- 

 ment, and to this extent live in different 

 worlds. Only when the receptors, through 

 which external conditions make their appeal, 

 are alike, are the outside conditions similar, 

 but as the stimulated organs vary, so do the 



