NATURE 



[March 3, 192 1 



particular, Dr. Mary Scharlieb, the doctor of 

 medicine, differs in emphatic terms from Dr. Marie 

 Stopes, the doctor of science and philosophy. 



The second, third, and fourth aspects of the 

 subject of the control of parenthood scarcely fall to 

 be reviewed in a journal like Nature, but the first 

 may fairly claim notice. Prof. Hill's contribution 

 is rather too closely packed with facts regarding 

 embryology, pregnancy, housing, and food to be 

 grasped easily in its significance ; but its author 

 is sturdily opposed to artificial means of prevent- 

 ing conception which " demand a premeditated act 

 in what should be a natural function and disturbs 

 the normality of the sexual act." Such a use of 

 preventives tells also far more against the woman 

 than the man. Prof. Hill sees the risks, the physio- 

 logical risks as well as the social, of the only 

 child. His solution of the problem of keeping 

 down the vigour of sexual desire is "a wisely 

 regulated diet, plvis hard physical exercise and 

 occupation." 



Prof. J. Arthur Thomson, from the point of 

 view of biology, writes with all his accustomed 

 picturesqueness of imagery, but the brilliancy of 

 his phrasing is somewhat of a danger, and may 

 even constitute a sort of verbal camouflage, a 

 risk which he himself seems to recognise when 

 in his closing paragraph he says : " We must not, 

 however, look at things too biologically ... we 

 are mind-and-body creatures, and the greatest 

 thing in human life is love." After enumerating 

 all the evils which may arise from birth control, 

 he directs attention to the fact that the good side 

 of the reduction of the birth-rate deserves more 

 consideration than it usually receives. It may 

 improve the health of both mothers and children, 

 give quality for quantity, render life less anxious 

 and earlier marriage more practicable, work 

 against war, make woman's position more inde- 

 pendent, and so forth. His contrast between the 

 keeping up of numbers by the fertility or spawning 

 method, with its unUmited production* of lives 

 the majority of which almost immediately cease, 

 and by what he finely designates "economised 

 reproduction associated with increased parental 

 care," is absolutely conclusive in favour of the 

 latter plan. 



The spawning solution among the lower animals 

 themselves is less effective in the long run than 

 that which Peripatus adopted — viz. the giving 

 birth to a few miniature adults ready at once to 

 fend for themselves. "The tapeworm, with its 

 degenerate body and drifting life of ease, has its 

 millions of embryos ; the golden eagle, with its 

 differentiated body and controlled life, has two 

 eaglets at a time." Yet it is not securely known 

 that high individuation directly lessens fertility, 

 NO. 2679, VOL. 107] 



for whilst some of the greatest men were child- 

 less a fair list of famous fathers can be made out. 

 After all, the strictly scientific or the rigidly bio- 

 logical aspect of human reproduction refuses to 

 be dissociated from the other ways of looking at 

 things ; and Prof. Thomson closes with words 

 which have weight : " If we lose the adventurous- 

 ness of early marriage on meagre material re- 

 sources, and the delight of having children while 

 we are young enough to sympathise with them, 

 we are missing- some of the fragrant flowers of 

 life." 



Our Bookshelf. 



Recueil de I'lnstitut Botanique Leo Errera {Uni- 

 versity de Bruxelles). Public par L. Errera. 

 Tome iv. Pp. xi -i- 653 -t- plates. (Brussels: 

 Maurice Lamertin, 1920.) 50 francs. 



This ponderous volume contains a selection of 

 papers published in various scientific journals from 

 1885 to 1900 by the late Lto Errera and other 

 Belgian botanists. There are a few short com- 

 munications by Errera at the beginning of the 

 volume of a general nature, such as those on the 

 law of the conservation of life, spontaneous 

 generation, and the mechanism of sleep. The 

 volume is mainly a collection of papers on plant 

 cytology and on the physiology of organisms of 

 simple structure. Workers specially interested in 

 these branches will appreciate the advantage of 

 associating in one volume a number of papers 

 scattered through many different journals, but as 

 all these journals are fairly accessible the pro- 

 duction of a great mass of reprints may seem 

 somewhat extravagant in view of the difficulties 

 attending scientific publication at the present time. 

 The volume contains thirty-two papers in all; 

 nineteen, mostly brief, are by Errera, including 

 one in which the inheritance of acquired characters 

 in a mould-fungus (Aspergillus) is maintained ; 

 others deal with protoplasmic movement, the 

 ascent of sap, and an apparatus to demonstrate the 

 mechanism of stomates. Communications by E. 

 Laurent and G. BuUot deal with the physiology of 

 growth and curvature of the fungus Phycomyces; 

 and Jean Massart discusses the sensibility to 

 various external influences of unicellular organisms 

 under several headings. The irritability of Nocti- 

 luca he describes as analogous to that of the Sensi- 

 tive Plant, the essential difference lying only in 

 the manner of the reaction. The longest paper is 

 by E. de Wildeman (published in 1893) on the 

 formation of the dividing wall in cells ; the sub- 

 jects of study were mainly species of mosses and 

 brown and red seaweeds. 



Manuel de Topomdtrie. Operations sur le Terrain 



et Calculs. By Jules Baillaud. Pp. vii4-'222. 



(Paris : H. Dunod, 1920.) 13 francs. 



In this book Capt. Baillaud sets down his war 



experience in the preparation of the plans neces- 



