November 23, 1917] 



SCIENCE 



513 



SCIENTIFIC BOOKS 



On Growth and Form. By D'Arct Went- 

 WORTH Thompson. Cambridge University 

 Press. 1917. 8vo. 779 pages with 408 

 text-figures. 



In the author's own words the purpose of 

 his book is to show " that throughout the 

 whole range of organic morphology there are 

 innumerable phenomena of form which are 

 not peculiar to living things, but which are 

 more or less simple manifestations of ordinary 

 physical laws." This thesis Professor Thomp- 

 son elaborates in a most interesting manner, 

 developing with the aid of our fuller knowl- 

 edge of physical forces and of the conditions 

 imder which they act, the mode of study 

 initiated by Borelli many years ago, and ap- 

 plied, more recently, with striking and sug- 

 gestive results, to several forms of organic 

 activity by Ehumbler, Leduc, Przibram, 

 Macallum and others. These results and 

 many others less familiar receive clear ex- 

 position, but the book is far from being a 

 mere compilation, a refreshing originality, 

 being characteristic both in subject matter 

 and in the manner of its presentation. 



The contest between the vitalistic and 

 mechanistic views of the phenomena of life 

 has been carried on by generation after gen- 

 eration of men and always with the strategic 

 results of the struggle in favor of the mechan- 

 ists, as one vitalistic stronghold after another 

 has fallen. The attack is drawing ever nearer 

 to the central citadel and Professor Thomp- 

 son's book is a massing of the attacking 

 forces before this citadel. But the author 

 with all his enthusiasm, recognizes limita- 

 tions in his resources. " "Not do I ask of 

 physics," he says," how goodness shines in 

 one man's face and evil betrays itself in an- 

 other. But of the construction and growth 

 and working of the body, as of all that is of 

 the earth earthly, physical science is, in my 

 humble opinion, our only teacher and guide." 

 Psychic phenomena are outside the limits of 

 his attack. Even with this limitation, how- 

 ever, the book is one of the strongest docu- 

 ments in support of the mechanistic view of 

 life that has yet been put forth. 



It would be difficult to give an adequate 

 resuane of the contents of a book, so crowded 

 with facts and ideas of the greatest interest 

 to morphologists ; it must suffice merely to 

 mention some of the problems treated. One 

 finds an interesting discussion of the physical 

 factors determining the size of organisms, 

 especially interesting being the consideration 

 of the conditions which may determine the 

 minimum size of a living organism. This is 

 followed by a chapter on the factors deter- 

 mining growth and then follow chapters on 

 the structure and form of the cell, in which 

 the phenomena of karyokinesis are regarded 

 as "analogous to, if not identical with those 

 of a bipolar electric field," and the forms 

 assvuned by organisms as expressions of the 

 law that a liquid film in equilibrium assumes 

 a form which gives it a minimal area under 

 the given conditions. In this connection 

 Professor Thompson expresses the opinion 

 that in the simpler organism, whose form is 

 due to the direct action of a particular phys- 

 ical force, similarity of form is not neces- 

 sarily an indication of phylogenetic relation- 

 ship. 



The form of the cell in cell-aggregates is 

 then taken up, the arrangement of the divi- 

 sion planes being considered as illustrations 

 of the principle of minimal areas, and the 

 author then passes on to the consideration of 

 concretions and spicules. This involves as 

 an essential problem the question of crystal- 

 lization in the presence of colloids, a question 

 concerning which there is much yet to^ be 

 learned. The further discussion of the forms 

 assumed by spicules leads to their division 

 into two groups, those of intracellular origin 

 and those that are intercellular, linear growth 

 of the former under restraint leading to forms 

 which have for their mathematical basis geo- 

 detic curves, while in the case of the latter 

 the phenomena of adsorption and the deposit 

 of the crystalline material on interfaces are 

 held to be sufficient for the explanation of 

 even the marvellously complicated radiolarian 

 skeletons. 



The mathematical properties of the log- 

 arithmic spiral as applied to the forms shown 



