244 



NA TURE 



[January 12, 1905 



defined above. The question cannot be discussed 

 on the present occasion, but it is well to bear in 

 mind that however completely the causes of evolu- 

 tion in the past may evade our attempts at demon- 

 strative proof, the history of evolution is a subject 

 which can be brought to the test. For many years it 

 has seemed to the writer that palaeontology can settle 

 decisively whether evolution has been continuous or 

 discontinuous. Those who desire to bring conclusive 

 evidence to bear upon this important controversy 

 would do well to follow the example of Prof. VV. B. 

 Scott, of Princeton, who told us at Cambridge that 

 he was " just crazy " over the fossil mammals of 

 Patagonia. 



In the last chapter, on adaptive variations, the 

 author would have done well to place in the forefront 

 the warning that a superficially apparent example " of 

 direct adaptation to surroundings in the ordinary 

 aicceptation of the term . . . may be the calling up, 

 in response to one of two stimuli, of one of two groups 

 of characters long since acquired by the plant proto- 

 plasm." The principle contained in these words 

 should be prominently before the mind of the naturalist 

 who attempts to investigate the response of an 

 organism to its environment. He should remember 

 that the species which he investigates are " heirs of 

 all the ages," thoroughly inured to experimental re- 

 search, past masters in the art of meeting by adaptive 

 response the infinite variety of stimulus provided bv 

 the environment. If he remember this he will always 

 be on his guard against a too hasty interpretation 

 based upon the fundamental properties of protoplasm. 



The discussion of the question, are acquired 

 characters inherited? (pp. 351 et seq.) is a particularly 

 interesting and suggestive introduction to the subject. 

 A few well chosen examples of the evidence chiefly 

 appealed to in support of such transmission are 

 followed by a brief but well balanced discussion. The 

 author supports the conclusion that the soma, and 

 through the soma the environment, e.xert a chemical 

 influence upon the germ-cells, and he makes effective 

 use of the " internal secretions " which hav'e marked 

 an epoch in physiological research. 



Several examples, generally believed to supply 

 evidence of the " cumulative action of conditions of 

 life " (pp. 352 et seq.), would be more satisfactory 

 and convincing if they were re-investigated as a piece 

 of special research. Too often they bear the impress 

 of an off-hand opinion without any secure foundation 

 upon specially directed inquiry. Thus, in the trans- 

 port of adult sheep or dogs to a different climate, it 

 may be expected that less change will be manifest in 

 the hairy covering of the parent than in that of the off- 

 spring which has been born and passed tlie whole of its 

 life in the new conditions. Thus the appearance, but 

 by no means necessarily the reality, of an accumulated 

 effect may be produced. In order to test the hypo- 

 thesis of accumulation, it would be necessary to neglect 

 the generation which has been subjected to two very 

 different environments and to determine quantitatively 

 with all possible accuracy the characters of those 

 which follow. The often repeated statements about 

 the telegonic effect of mating " Lord Moreton's mare " 

 NO. 1837, VOL. 71] 



with a male quagga, when compared with the results 

 of Prof. Cossar Ewart's researches, prepare us for the 

 belief that many a general impression which has been 

 produced as evidence will collapse when it has become 

 the subject of searching and critical investigation. 



In the preface the author speaks with some diffi- 

 dence of the prominence given to his own researches. 

 Investigations such as those into the effect upon off- 

 spring of the relative freshness or staleness of the 

 parental germ-cells would, in any circumstances, be 

 an unfortunate omission from a book on variation. 

 They are, moreover, described in the publications of 

 scientific societies not always freely accessible to the 

 general reader. For another reason also the book 

 would have suffered if these researches had been treated 

 less fully. When the author of a general work is not 

 altogether wanting in the sense of fitness and propor- 

 tion, the account of his own contributions to science 

 will probably be the salt of his book. These subjects 

 stirred his own enthusiasm for research, and in writing 

 of them he is likely to stir the enthusiasm of others. 



E. B. P. 



MATHEMATICAL THEORY OF ECLIPSES. 

 The Mathematical Theory 0/ Eclipses, according to 

 Chauvenet's Transformation of Bessel's Method. 

 Explained and illustrated by Roberdeau Buchanan, 

 S.B. Pp. x-(-247. (Philadelphia and London: 

 J. B. Lippincott Co., 1904.) Price 31s. net. 



WHEN a practical man devotes himself to the 

 task of explaining to others the difficulties of 

 any specialised subject on which he has been engaged 

 for many years, the result is likely to be satisfactory. 

 There is always the chance that the prolonged study 

 of one particular subject has had the effect of unduly 

 exalting its importance, with the consequent loss of 

 a proper perspective, and when one sees a compara- 

 tively narrow branch of astronomical inquiry, like 

 eclipses, occupying a rather ponderous volume, he may 

 be led to think that the subject has been indiscreetly 

 expanded. We therefore hasten to say that there is 

 no evidence of disproportionate treatment in Mr. 

 Buchanan's book. He himself has been employed for 

 twenty-three years in the office of the " American 

 Ephemeris and Nautical .\lmanac," and during that 

 time has been responsible for the accurate preparation 

 of the necessary information connected w-ith eclipse 

 prediction. His practical acquaintance with the sub- 

 ject eminently fits him for the task he has undertaken, 

 and his book is a success. The moon's nodes have 

 made more than one complete revolution since he 

 began his work, and an entire series of eclipses has 

 revealed to him their peculiarities and oddities. 



The theory of eclipses has been well explained by 

 various astronomers, and practical rules given by 

 some. Hallaschka, in his " Elementa Eclipsium," 

 following the method of orthographic projection, has 

 worked out an example in full. Woolhouse, in the 

 appendix to the " Nautical Almanac " for 1S36, not 

 only discussed the subject with great fulness, but 

 gave practical rules for the determination of the 

 phenomena, which for many years were followed in 



