424 



NATURE 



[October 7, 1909 



They are supposed by the official geologists of the 

 U.S. Survey and others to include large masses of 

 altered Paleeozoic sediments, while the author sup- 

 ports the alternative opinion that most of these rocks 

 are Pre-Cambrian. The Triassic rocks of the 

 western side of the Hudson River, with their intrusive 

 diabase which forms the picturesque Palisades, and 

 the sparingly exposed Cretaceous strata of Staten 

 Island are the only other " solid " formations known 

 in the neighbourliood of New York. 



The drift deposits and their associated phenomena, 

 evervwhere conspicuous, afford the subject for the 

 final chapter of the book, which the author presents 

 in a strain calculated to impress the uninitiated. 



The arrangement of the book is somewhat con- 

 fusing to the outsider, being based on the municipal 

 divisions of the city. The style of writing is often 

 turgid, over-ornamented, and not particularly 

 accurate. \ region is described as of " pene-Saharal 

 loneliness"; there have been " loculicidal slippings " 

 in the gneiss (the botanical adjective looking quite 

 aggressive here) ; the drifts " tell the singular story 

 which the long, tireless and infinite retinue of 

 glacialists has been engaged in translating these long 

 years"; and so on. Misprints are numerous, even 

 in the preface " carefully " appearing as " carfully "; 

 the so-called " bibliographies " contain few proper 

 references ; and there is no index to the volume. 



In some appended notes on the archaeologv of Man- 

 hattan Island, some relics of the British army en- 

 gaged in the Revolution are mentioned; and, con- 

 sidering the recency of the period, it seems curious to 

 read that " the habits and life of the soldierv have 

 been traced by the remains of their food, utensils, 

 pikes, cutlery." G. Vv'. L. 



THE LA WS OF INHERITANCE. 



Elemcntc der exakten Erblichkeitslehre. Deutsche 

 wesentlich Erweiterte .'\usgabe in Fiinfundzwanzig 

 Vorlesungen. By W. Johannsen. Pp. vi + 516. 

 (Jena : Gustav Fischer, 1909.) Price 9 marks. 



WITHIN the last few years the output of exact 

 experimental work upon phenomena of here- 

 dity has been very large, and the progress made, as 

 compared with that of the previous forty vears, has 

 been astounding. In England it has chiefly been 

 produced by investigator? who have strictly segre- 

 gated themselves either to the Mendelian or the bio- 

 metrical schools, and who as a rule seem unable to 

 icalise the merits of the work of their rivals. One may 

 pause in astonishment on reading, in a recent work 

 issued by the head of the Mendelian school, that 



" Of the so-called investigations of heredity pursued 

 by extensions of Galton's non-analytical method and 

 promoted by Prof. Pearson and the English bio- 

 metrical school it is now scarcely necessary to speak. 

 That such work may ultimatelv contribute to the 

 development of statistical theory cannot be denied, but 

 as applied to the problems of heredity the effort has 

 resulted only in the concealment of that order which 

 it was ostensibly undertaken to reveal. . . . With the 

 discovcrv of segregation, it became obvious that 

 methods dispensing with individual analysis of the 

 material are useless." 



NO. 2084, VOt,. 81] 



Most biologists, with no axes to grind, are able to 

 appreciate the importance of the work of both schools, 

 though at present it is scarcely possible for them to 

 judge whether the work of the one is destined to be 

 of more permanent value than that of the other. The 

 mutually destructive criticism of the two, though not 

 without value in stimulating healthy competition, has 

 the unfortunate result that the biologist who is wedded 

 to neither school finds it difficult to lay his hands 

 upon an adequate but impartial description of their 

 methods and results. To such we can cordially re- 

 commend the work on inheritance, by Prof. Johann- 

 sen, now before us. The Danish edition of this book 

 was published in 1905, but the present edition is 

 double the size of the original, and is practically a 

 new work. It consists of twenty-five lectures, in the 

 first eight of which the facts of variation and itsj 

 statistical study are discussed. The author then 

 describes at some length his own very interesting 

 experiments upon a " pure line " of self-fertilised beans 

 (Phaseolus), which he bred for six generations. He 

 found that selection within such a pure line did not 

 lead to departure from the type, i.e. beans grown from 

 a small bean were exactly the same size as those 

 grown from a large bean of the same plant. He 

 designates these non-heritable variations in size as 

 " fluctuations." These results have coloured the 

 author's outlook upon problems of segregation, muta- 

 tion, and selection, and before accepting his interpre- 

 tation the criticism of his experimental results by 

 Prof. Pearson and the late Prof. Weldon should be 

 studied (" Biometrika," ii., p. 499). 



In subsequent lectures the author discusses discon- 

 tinuous variation, correlation, regression, and the 

 effects of conditions of life, and then passes on to 

 describe Mendel's law and de Vries's theory of muta- 

 tion. Darwin's principle of natural selection acting 

 continuously upon small, indefinite variations finds 

 but small favour in his eyes, and he attributes the 

 origin of species to the appearance of mutations and 

 the production of new races by crossing, the new- 

 characters being propagated unchanged in accordance 

 with Mendel's law. .Selection produces nothing, but 

 extirpates unfavourable mutations, and so leaves rooni 

 for new and favourable ones. However, the author 

 makes no attempt to explain how mutations, in spite 

 of their extreme rarity, have been able to effect so 

 much. Hence, as is only to be expected, these views 

 on heredity, though worthy of full consideration, must 

 be studied in a critical spirit. H. M. Vernon. 



OUR BOOK SHELF. 



A Sketch of the Geograpliy and Geology of the 



Ilimalava Mountains and Tibet. Bv Col. S. G. 



Burrard, R.E., F.R.S., and H. H. Hayden. Part 



iv. The Geology of the Himalaya. (Calcutta : 



Government Printing Office, 1908.) Price 2 rupees. 



The fourth part of the sketch of the geography and 



geology of the Himalayas is entirely the work of Mr. 



H. H. Hayden, and is devoted to a review of the 



present state of our knowledge of the Himalayas. 



This knowledge is fragmentary ; of the Himalayas 



east of Sikkim only a few small patches, and these 



close to the southern margin, have been visited, then 



