REVIEWS 333 



has been accepted as satisfactory by the philosophic biologist. Arrhenius's sug- 

 gestion that life was introduced on to this earth at some remote period from 

 somewhere in space is perhaps the least acceptable of all. It leads us nowhere, 

 but leaves us blindly drifting through the ether in a search for imaginary con- 

 ditions under which life might conceivably have originated with but the slenderest 

 of data on which to build our concept of the physico-chemical environment on any 

 other planet. It is our bounden duty to do our utmost to seek for life's com- 

 mencement on this earth until it can be shown beyond doubt either that it could 

 not have originated here or that it did start elsewhere. Darwin's theory, 

 while giving a possible explanation of the origin of form differences, seems to 

 depend entirely on chance, both for the origin of its variations and of life, and the 

 former of these, at any rate, is not borne out by palaeontological evidence. 

 Bergson's Elan vital is a principle so mystic in its essence that it eludes all our 

 efforts to grasp it. 



Not merely does Osborn forsake the biological line of attack but adduces a 

 number of cogent reasons against it ever yielding a solution to the problem which 

 he claims must be sought along physico-chemical lines, and, since all questions of 

 metabolism must be solved in this way, there is a great deal to be said for this 

 point of view. Thus it is that to a biologist the introductory chapters prove 

 provocative, for he is forced to relinquish thinking in terms of form and think 

 in terms of the energy that produces the form. This thinking in terms of form 

 and form transformation in the past has undoubtedly led to the formulation of 

 laws of evolution, but they carry us no further in our search for causes, and to get 

 at these we must think in terms of energy complexes, of which form is but the 

 visible expression. 



The idea of Action and Reaction have long been familiar to the physicist, as 

 has the second law of thermodynamics, and the author's main thesis is that in 

 applying these concepts to living matter another factor needs to be considered : 

 "Every physico-chemical action and reaction concerned in the transformation, 

 conservation, and dissipation of energy, produces also, either as a direct result or 

 as a by-product, a physico-chemical agent of interaction which permeates and 

 affects the organism as a whole or affects only some special part." It is this 

 interaction which unifies and co-ordinates the activities of the organism as a 

 whole, so distinguishing it from inorganic substances, and so it is necessary to 

 trace the origin of this interaction. This idea is to a certain extent like the 

 internal adjustment of Spencer. 



This quest leads the author to a consideration of the inorganic environment, 

 the age of the earth, the elements essential to life, and the possibility of chemical 

 combinations of some complexity, ultimately leading to the evolution of some form 

 like the very lowliest of the bacteria. Whether one agrees with them or not, it is 

 impossible not to be interested in the speculations so well put forward. Once this 

 territory has been passed, of course the speculations become less, and the way up 

 to the higher animals and plants is indicated in the author's well-known expository 

 manner, so that the latter part of the book forms an interesting account of the 

 general evolutionary trends of the main groups, and is naturally fully illustrated 

 by reference to palaeontological discoveries. 



We have to note one slip. In the footnote on p. 235 Dr. Elliot Smith is 

 described as of the University of Glasgow, whereas he is at the University of 

 Manchester. 



In brief then we have here one of the most interesting biological books that 

 has appeared for some years, and it is assured of a wide welcome from naturalists 

 22 



