8 4 



NATURE 



[March 27, 1913 



and the wide view which is taken of the subject 

 is further reflected in the sections at the end of 

 the book devoted to non-parasitic diseases (caused 

 doubtless by disturbances in physiological balance 

 generally and in enzyme secretion particularly) 

 and to various abnormalities in growth. 



F. C. 



The Bradshaw Lecture on the Biology of 

 Tumours. By C. Mansell Moullin. Pp. 39. 

 (London: H. K. Lewis, 1913.) Price 2s. net. 

 Mr. .Mansell Moullin has published as a booklet 

 the Bradshaw lecture which he recently delivered 

 before the Royal College of Surgeons. It treats 

 of new growths or tumours from the biological 

 point of view ; he regards the division of them 

 into malignant and innocent as a mere useful 

 convention ; there is no sharp line of demarcation 

 between the two groups. He prefers a division 

 into those which spring from germ-cells and 

 possess a more or less complete individuality, and 

 those which spring from somatic cells and are 

 due to escape from control of what remains to 

 them of their primitive form of growth. The short 

 course of an hour's lecture precluded any full 

 treatment of this large subject. The various 

 theories of malignancy are not discussed, but the 

 parasitic nature of cancer is denied. With regard 

 to cure, we have the confession that at present the 

 surgeon's knife is the only safe remedy, though 

 the lecture concludes with the hope that this will 

 not always be so. No reference is made to the 

 part chemistry has played or will play in the 

 elucidation of the cancer problem. Until we know 

 what are the biochemical or metabolic actions in 

 the cells of a new growth, we can scarcely hope 

 to grapple with the methods which will ensure 

 recovery. W. D. H. 



The Physical and Political School Atlas. By J. G. 

 Bartholomew. Pp. xvi of uncoloured maps and 

 texts ; 32 coloured maps. (London : Oxford 

 University Press, 1913.) Price is. net. 

 This cheap and trustworthy atlas may be com- 

 mended to the attention of teachers of geography. 

 The attempt in some cases to show land relief and 

 other physical features as well as the political 

 geography of a country on one and the same map 

 his led to overcrowding and indistinctness. Where 

 this mistake has been avoided the maps are bold, 

 clear, and convincing. 



"Half-inch in Mile " Map of England and Wales. 

 Sheet 3. Cumberland, &c. New and revised 

 edition. (Edinburgh : John Bartholomew and 

 Co., n.d.) Price, in case: is. 6d. paper; 2s. 

 on cloth, or 2s. 6d. on cloth dissected. 

 Like other maps in this excellent series, this of 

 the Lake District is reduced from the Ordnance 

 Survey, and has been revised to date. The map 

 is coloured in the now familiar browns and greens, 

 and in consequence the surface relief can be under- 

 stood with ease. All details likely to be required 

 by tourists and sportsmen are indicated, and 

 altogether this sheet well maintains the high 

 reputation of the series. 



NO. 2265, VOL. 91] 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended fur 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



The Falling Birth-rate. 



In her lecture, delivered at University College, Lon- 

 don, on February 25, .Miss Hlderton, ol the Gallon 

 Laboratory, in dealing with the falling" birth-rate, 

 pointed out that the decrease is least acute in the 

 mining districts ; the engineering trades, which re- 

 present the best paid of the artisan class, come next; 

 while textile districts coincide with residential dis- 

 tricts in showing the biggest decrease ; and she asks 

 if there is some cause which operates to a special 

 degree in certain classes. 



One important operating cause, no doubt, is the 

 large and increasing number of women employed in 

 the textile trades. On the other hand, with the ex- 

 ception of a few pit-brow girls, practically no females 

 are employed in the mining and engineering indus- 

 tries ; and it is, therefore, perhaps scarcely surprising 

 to find a greater birth-rate amongst the wives of 

 miners and engineers than amongst the women in the 

 cotton and woollen districts. The married woman 

 operative in the Lancashire cotton mills, for example, 

 knows that each new addition to the family entails 

 some weeks' loss of work and wages before and after 

 her confinement, and it also means an increased 

 weekly charge when the baby is, according to Lan- 

 cashire custom, "put out to nurse"; and no doubt 

 this knowledge acts as a considerable check upon the 

 birth-rate. 



The decrease in the residential districts is due, no 

 doubt, in part, to the "increase in luxury of living 

 and love of pleasure" referred to by Miss Elderton, 

 and in part also to the comparatively large number 

 of women who are employed in such districts in 

 domestic service. The rise in the average marriage 

 age must also be taken into account. 



Nor must we forget the influence of education. 

 It is worthy of note that the fall in the birth-rate in 

 this country practically dates from the passing of the 

 Education Act in 1S70. This new influence would 

 make itself felt in a variety of ways. The check on 

 the employment of child labour, for example, would 

 tend to act as a check on the birth-rate, for whereas 

 formerly children became wage-earners at a very 

 tender age, they would, after the passing of the Act, 

 not only cease to be wage-earners, but would actually 

 be an increased charge on the parents. The increase 

 in the knowledge of physiology, which has spread in 

 recent years as a result of free education, may also 

 not be without its influence. 



Yet another factor — again ascribable not very in- 

 directly to free education — is the change in religious 

 sentiment which has been so pronounced during the 

 last quarter of a century. Among other things, people 

 are beginning to doubt whether, in these days, the 

 "quiver full" of children is the unqualified blessing 

 which the Psalmist declared it to be. They are 

 realising that it is better to be the parent of two or 

 three children, well provided for, than of a half-score 

 or so of starvelings. 



Miss Elderton also tells us that "a further analysis 

 of figures for several northern towns shows generally 

 that the higher the wages the smaller the family." 

 This is exactly what, other things being equal, one 



