Jtinc 23, 1887] 



NATURE 



171 



lastly, it renders possible the total regeneration of the 

 nucleus. In the present state of our knowledge, how- 

 ever, there is obviously much that is hypothetical in the 

 respective importance of these consequences. 



It is chietly in his researches on the embryology of 

 Nematoda that Prof. Carnoy has reached conclusions which 

 are totally at variance with those already arrived at on the 

 same subject by Messrs. Nussbaum and E. Van Beneden. 

 We allude especially to the mode of formation of the 

 polar bodies in the c%g of Ascaris megalocepJiala. For 

 the Louvain Professor, the two successive divisions which 

 take place in the germinal vesicle assume the following 

 characters : — 



(i) The nuclear element (''cldment nucleinien typique") 

 of the egg of Ascaris niegalocephala becomes at an early 

 stage broken up into eight nearly equal rod-like portions ; 

 these at once separate into two groups of four rods 

 (" batonnets "), thus constituting the Wagnerian spots. 



(2) When a spermatozoid has made its way into the 

 ^gg, sometimes very soon afterwards, occasionally later, 

 an alteration of the germinal vesicle becomes visible ; its 

 membrane dissolves away, and subsequently, by a process 

 of true karyokinetic division accompanied by the forma- 

 tion of asters of remarkable variety and complexity, the 

 first polar body is expelled. This he finds to consist of 

 four nuclear rods and a portion of the protoplasm of the 

 ^gg. At this stage, therefore, according to Dr. Carnoy, 

 four rods only remain within the egg. 



(3) Now the same process begins again, in all essential 

 respects resembling that which has just been described ; 

 finally, the second polar body is expelled in its turn. It 

 consists of two nuclear rods, so that only two rods remain 

 now in the ^%g for the formation of the female pro- 

 nucleus. We are thus in a position to calculate accurately 

 the amount of nuclcin lost by the germinal vesicle during 

 the expulsion of the polar bodies. According to Prof. 

 Carnoy, the loss, for Ascaris niegalocephala, would amount 

 exactly to three-fourths of the nuclein originally present 

 in the ^ZZ- 



We are not sure whether Prof. E. Van Beneden's views on 

 this delicate question may not be to a certain extent recon- 

 ciled with those of the eminent biologist of Louvain, 

 especially as regards the number of nuclear portions 

 contained in the first polar body. But respecting the 

 constitution of the second polar body the views of the 

 two Belgian observers are certainly difficult, if not im- 

 possible, to reconcile. 



Prof. Carnoy's book reads easily, and his statements 

 are always clear and definite. The text is illustrated 

 by a large number of figures, beautifully executed, which 

 greatly enhance the value of this most interesting and 

 important work. 



L. Martial Klein. 



OUR BOOK SHELF. 



The Climatic Treatment of Consumption: a Contribution 

 to Medical Climatology. By J. A. Lindsay, M.A., M.D. 

 (London : Macmillan and Co., 1887.) 



Dr. Lindsay does not profess to have written a system- 

 atic and exhaustive treatise upon the climatic treat- 

 ment of consumption. He holds that we are only on the 

 threshold of climatological investigation : and " for its 



exhaustive discussion," he says, "prolonged inquiry will be 

 necessary, and more exact methods than those hitherto 

 generally employed." He has made, however, an im- 

 portant contribution to the study of a v'ery difficult sub- 

 ject, and his book ought to be of much service not only to 

 physicians but to many sufferers who may still hope to 

 find in climatic treatment a powerful adjunct to hygienic 

 and medical measures. Having discussed the causes of 

 consumption and the general principles of climatic treat- 

 ment, Dr. Lindsay presents a general view of the chief 

 sanatoria for consumption. He then describes mountain 

 sanatoria and the ocean voyage, and gives a full and trust- 

 worthy account of sanatoria he himself has visited, 

 including Australia, Tasmania, New Zealand, California, 

 the Cape, .Mgeria, Southern France, and the home sana- 

 toria. The value of the book is, of course, greatly 

 increased by the fact that he has relied for his informa- 

 tion mainly on personal observation. 



I llustrations of the British Flora. Drawn by W. H. 

 Fitch, F.L.S., and W, G. Smith, F.L.S. Second 

 Edition. (London: L. Reeve and Co., 1887.) 



When the illustrated edition of Bentham's " Hand-book of 

 the British Flora " was exhausted, the wood engravings of 

 that work were reproduced in a volume intended to serve as 

 a companion to the " Hand-book" and other British Flor is. 

 The volume has been so popular that the publishers have 

 found it necessary to issue a second edition ; and they 

 have taken pains to secure that it shall be more useful 

 than ever to students of botany, and especially to begin- 

 ners. Five cuts have been added, and the arrangement 

 of all the illustrations has been brought into accordance 

 with Bentham's " Hand-book " as it has been revised by 

 Sir J. D. Hooker. To facilitate reference from other 

 Floras, the index has been greatly enlarged, and there is 

 a new index of English and popular names. 



Sketches of Life in fapan. By Major Henry Knollys, 

 R.A. With Illustrations. (London : Chapman and 

 Hall, 18S7.) 



i In this book Major Knollys undertakes to tell us some- 

 thing of " the minor lights and shades " of the social life 

 of Japan. He is a careful observer, and writes brightly 

 and pleasantly ; and no doubt the lively record of his 

 impressions will interest a good many readers who would 

 not have cared to study a more elaborate and systematic 

 account of the Japanese people. The substance of the 

 book was written " on the spot," but all statements with 

 regard to matters of fact have been carefully revised. 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he under- 

 take to return, or to correspond zvith the writers of, 

 rejected manuscripts. A''o notice is taken of anonymous 

 communications. 



[ The Editor urgently requests correspondents to keep their 

 letters as short as possible. The pressure on his space 

 is so great that it is impossible otherwise to insure the 

 appearance even of communications containing interesting 

 and novel facts.] 



Thought without Words. 



There appears to be some ambiguity about this matter as dis- 

 cussed in the correspondence which has recently taken place in 

 your columns. In the first instance Mr. Galton understood 

 Prof. Max Miiller to have argued that in no individual liuman 

 mind can any process of thought be ever conducted without the 

 mental rehearsal of words, or the vcrbum mcnlate of the School- 

 men. Now, although this is the view which certainly appeai-s 

 to pervade the Professor's work on " The Science of Thought,' 

 there is one passage in that work, and several passages in hi.s 

 subsequent correspondence with Mr. Galton, which express quite 



