August 3, 1905] 



NA TURE 



;i5 



as the most recent exposition of that naturalist's 

 views and researches, and partly as the first account 

 of them available in the English lang-uage. 



It has been maintained bv those who attack bio- 

 lotrical problems by methods by which they insist 

 that they do not hope to account for anything, that 

 it is idle to attempt to explain the phenomena of 

 variation and heredity until they have been adequately 

 described ; and although it is certain that the danger 

 of a too premature attempt to account for things is 

 greater among those who use methods by which they 

 believe the fundamental nature of the things will 

 ultimately be revealed than it is among statistical 

 evolutionists, it does not follow that it is better to 

 adopt the second course on account of these (reallv 

 not very dangerous) pitfalls in the first. Of the 

 possibility of adopting it without falling into them at 

 all Prof, de Vries's work is a rare example. The 

 book before us consists of twenty-eight lectures de- 

 livered at the California University by Prof, de Vries, 

 and prepared for the press by Mr. D. T. MacDougal. 

 It will be of immense value to the student whose lack 

 of knowledge of German renders " Die Mutations- 

 theorie " a sealed hook to him, as well as to the 

 investigator; but two features of it, which result 

 from the mode of its origin, render it a less valuable 

 work than " Die Mutationstheorie." One of them, 

 which affects the student and general reader, is the 

 absence of illustrations ; the other, which affects the 

 investigator, is the absence of references, which is a 

 real drawback in a book that puts into circulation 

 the details of many unfamiliar and interesting breed- 

 ing experiments. 



Seeing that this book is likely, and intended, to 

 appeal to the student, there is one feature of it which 

 might have been different with advantage; and we 

 believe the defect to be serious, because the general 

 reader will notice it as little as he will deplore the 

 absence of pictures much. 



The publication of a book in which there is set 

 forth for the student a new and profoundly important 

 biological theory, and a collection of facts in support 

 of it, seems to us to have been a most suitable oppor- 

 tunity for discarding that scientific jargon which is 

 still believed to have a meaning by those who do not 

 understand it, and still used by those who know that 

 it means nothing. In the very first sentence it appears 

 in its old vigour. .':'.' -. 



" Newton convinced his contemporaries i^at natural 

 laws rule the whole universe. Lvell- showed.' bv his 

 prmciple of slow and gradual evolution: th.il natural 

 laws have reigned since the beginning of limc-."- '■'■ - 



Of course Prof, de Vries and- Mr; -MacDougal know 

 that natural laws do not really, fii]e-.t]he:jjhiverse, .and 

 that they have not reigned sinie .the' beginning of 

 time, and that this latter expre_ssipn : .stretches- aven 

 poetical licence. But the generalixMder a'nd . stu'dent 

 do not know this, and when they sfee'thi^i -kind of 

 statement scattered through scientific literature they 

 can be pardoned for going away/ with the idea that 

 there must be laws existing, i'pragwhere ruling and 

 reigning and being obeyed./^i^d.'that it is the busi- 

 ness of the man of science. tp discover them. '; 

 NO. 1866, VOL. 27] 



.V few examples from the body of the book will 

 suffice. For instance, on p. 3, " If an origin by 

 n.'itural laws is conceded for the latter, it must, on 

 this ground, be granted to the first also"; on p. go, 

 "... wild species, which obey the laws discussed 

 in a previous lecture "; on p. 175, "... and liable 

 to reversions by the ordinary laws of the splitting up 

 of hybrids "; and on p. 547, " The physiological laws, 

 however, which govern this process are only very 

 imperfectly revealed by such a study." 



We are perfectly aware that such expressions are 

 continually to be found in the memoirs of men of 

 science who in their other writings have exposed the 

 meaninglessness of such phrases ; but this onlv leads 

 to the necessity of a stronger insistence on the 

 desirableness of discarding them, in the conviction 

 that the curious image of nature which such ex- 

 pressions call up would be less erroneous and more 

 eradicable than it is now if they were never used. 



The fact that entirely different things sometimes 

 have the same name leads to the need for caution 

 in the interpretation of another expression the mean- 

 ings of which are about as numerous and as different 

 as those of the term "law." The word regression 

 in Prof, de Vries's book denotes a biological pheno- 

 menon of singular interest ; but it must not be for- 

 gotten that it is also the name of a purely statistical 

 conception. It is ve;ry necessary that these two 

 significations should be kept absolutely distinct in the 

 mind of the reader. 



- The book is, considering its bulk, very free from 

 misprints; the few that occur do not lead to any 

 difficulty, e.g. " begining" on p. 118, " hnudred " 

 on p. 475, " of " for " on " in the last line of p. 560. 

 There is one inconsistency of spelling ; Macfarlane is 

 spelt thus on pp. 21 and 268, and with a capital F 

 on p. 255. We have some doubt as to which is the 

 more correct, " morphologic " or " morphological," 

 though we have none as to which is the more 

 euphonious; but surely one or the other should be 

 used throughout; yet on p. 141 we find "morpho- 

 logical " and on p. 144 " morphologic," and similarly 

 on p. 144 "physiologic" and on p. 547 "physio- 

 logical," on p. 709 "empiric" and on p. 733 

 " empirical. " . 



We think that scant justice is done to the greatness 

 of Mendel's work and to the conceptions based upon 

 it which bid fair to put us on the track of accounting 

 for some of the phenomena of hereditv; and by con- 

 fining Mendel's law to the description of the mutual 

 properties of varieties only, the meaning and tendency 

 of Mendelian investigation that is now being carried 

 on seem to be mi^ed. That Hurst can predict the 

 difference- between the result of mating two pairs of 

 rabbits externally identical, by means of a knowledge- 

 of the difference between their gametic constitutions 

 acquired by previous breeding from them, constitutes, 

 I it seems to us, the longest stride the study of heredity' 

 has made for some time past. 



The zoologist who confines himself as strictly to' 

 the study of animals as Prof, de Vries does to that of' 

 plants will be disappointed if. trusting to the com-' 

 prehensiveness of the title of the book, he expects to' 



