January 13, 192 1] 



NATURE 



623 



When it is stated that the "unfit" are eliminated, 

 we may ask, Unfit for what? Is not the state- 

 ment on p. 16 1 that "union is never voluntary" 

 rather too sweeping? Warfare in most minds is 

 ■-sociated with the idea of destruction — that is, 

 ot waste. This is perhaps not an essential part 

 of its meaning-, and the reviewer is aware that 

 his point of view may not be that of other readers 

 of the book. 



Turning to the second essay — that on 

 Malignancy " — we note that the author, after 

 profound discussion of various views, comes 

 to the conclusion that it is due to the failure 

 of the mutual action of connective-tissue and 

 epithelium on one another, perhaps under the in- 

 fluence of some internal secretion. We may com- 

 pare the view put forward by Dr. A. Paine in 

 the Lancet of October 2, in which the noxious 

 influence of certain irritants, especially of bacterial 

 toxins, is held to be responsible for the degenera- 

 tion of the specialised functions of the epithelial 

 cell, so that it returns to its embryonic state. If 

 Mr. .Morley Roberts's conclusion is correct, we 

 jire led to regard much of the cancer research of 

 the present day as beginning at the wrong end, 

 so to speak. We must learn more about the 

 normal dependence of one tissue on the activities 

 of another before we proceed to examine what 

 happens when this dependence is disordered. Too 

 much direct attack is made on disease before an 

 accurate knowledge of what health really is has 

 been obtained. In this connection we may refer 

 to the apt illustration by the author on p. 4, 

 ■where it is pointed out that it would be absurd 

 to think of learning how to build a ship by ex- 

 amination of wrecks on the shore. 



These considerations may be commended to the 

 ■ention of the Ministry of "Health." In fact, 

 the investigation of cancer, as in that of im- 

 JBjnunity, too narrow a point of view is often 

 ^■Ucen. The author rightly insists (p. 64) on the 

 ^vital importance of taking account of work in 

 ^Branches of .science other than that actually in 

 ■j^ew. It must often strike even the moderately 

 'cultured investigator how sadly lacking in know- 

 ledge of general principles so many of the workers 

 in specialised subjects are apt to be. Many in- 

 dustrial "inventors" would save themselves much 

 trouble, ;is well as loss of money, by learning more 

 about the fundamental principles of science. This 

 Jack is perhaps particularly noticeable in those 

 <Jevotctl to the subject of immunity, although 

 there are, of course, notable exceptions, and much 

 excuse must be made owing to the unfortunate 

 domination of the Ehrlich phraseology, against 

 which our author justly protests (pp. 127, etc.). 

 Ashr points out, we cannot explain a bacterio- 

 VO. 2672, VOL. 106] 



logist by saying that he is bacteriological. One is 

 sometimes inclined to wish that some gifted in- 

 vestigator who knows nothing of previous work 

 on immunity would attack the problem at its 

 foundations. 



The third essay is of much interest. Dealing 

 with the problem of repair, it propounds the thesis 

 that the evolution of an organ is frequently a case 

 of the mending of a breakdown. This opinion, 

 although supported with much evidence, will 

 probably evoke some dissent. But all readers will 

 agree that there are gaps in our knowledge of 

 the processes of repair and of hypertrophy result- 

 ing from functional activity. The author's views 

 on direct adaptation are also difficult to accept in 

 their entirety. Although the accessibility of the 

 germ plasm to chemical agents, as in Stockard's 

 experiments with the action of alcohol on guinea- 

 pigs, cannot be denied, there is no reason to 

 suppose that a modification would be of such a 

 kind as to be appropriate in combating the change 

 in the environment. One is somewhat surprised 

 to find that the author accepts the statements of 

 Abdcrhalden with respect to the production of 

 "protective enzymes." 



Turning to another interesting question — that 

 of inhibition— it is curious that the author, 

 although making use of the conception in the 

 case of the nervous .system, finds difficulties in 

 the action of the vagus nerve on the heart. This 

 may be due to the interpretation he puts on the 

 word "depressant." Inhibition, whatever ex- 

 planation we may try to give of the way in which 

 it is brought about, means no more than stopping 

 a process or reducing its intensity, no harm being 

 done to the active cells. Neither is it a question 

 of diverting "energy" in another direction. The 

 author has overlooked Sherrington's experiments 

 which show that a reflex can be inhibited without 

 evoking any other reflex. The reviewer must con- 

 fess, however, that he is at a loss to understand 

 what the difficulty with the cardiac vagus really 

 is. We find also some unnecessary trouble made 

 about "trigger action." The physiologist under- 

 stands by this expression merely that the work 

 required to set a process in action has no relation 

 to that set free as a result. It may be that a 

 measurable amount of work is needed to move 

 a trigger, but the energy set free in the cartridge 

 is just the same whether the trigger moves stiffly 

 or easily. One would also like to have a little 

 more explanation of what the author means by 

 " shock " as applied to cells. 



This list of criticisms may be ended wiUi oiu 

 of a different kind. On p. 169 it is suggested 

 that there is an advantage in cannibalism owing 

 to the fact that the food has a similar nature to 



