NATURE 



[September 26, 19 12 



OUR BOOKSHELF. 

 Norse Tales. By Edward Thomas. Pp. 159. 



(Oxford : The Clarendon Press, 1912.) Price 2s. 

 This book is a successful attempt to popularise 

 the romance and poetry of ancient Norse litera- 

 ture. Though he has not quite attained the 

 dignity and charm of style which render Sir G. 

 Dasent's "Story of Burnt Njal " and the "Popular 

 Tales " from the collection of Asbjorsen classics in 

 our folk-lore literature, this presentment by Mr. 

 Thomas ofi'ers little ground for criticism. 



The collection falls into two parts : — first, 

 stories of the gods, a rearrangement of the Prose 

 or Younger Edda, compiled by Snorri Sturleson 

 in the thirteenth century ; secondly, an adaptation 

 of the excellent collection of early poetry made 

 by Gudbrand Vigfuson and F. York Powell, under 

 the title of "Corpus Poeticum Boreale." Mr. 

 Thomas, perhaps wisely, does not discuss at 

 length the many problems of the Eddas. All that 

 is certain is that the poems were collected in 

 Iceland, that some bear internal evidence of being 

 older than others, and that they assumed their 

 present shape long after the time of their com- 

 position. The land in which they were originally 

 written is still uncertain. The editors of the 

 " Corpus Poeticum Boreale " suggest that some 

 may have their origin in these islands, or may 

 have been re-edited here "at a time when the 

 Irish Church, with her fervent faith, her weird 

 and wild imaginings, and curious half-Eastern 

 legends, was impressing the poetic mind on one 

 side, while the rich and splendid court of Eadgar 

 or Canute would stimulate it on the other." 



The introduction by Mr. Thomas is excellent, 

 so far as it goes. But as the book seems to be 

 intended for school use, it might with advantage 

 have been extended, and a bolder attempt might 

 have been made to prepare the student for the 

 assimilation of much that is unfamiliar. We 

 must, however, be thankful for what he has 

 given us: "The Making of the Worlds, of Gods, 

 and of Giants " ; the twisting of Loki in the cave 

 which causes earthquakes; the tale of Balder and 

 Loki, where a note might have been added to 

 direct the reader to Prof. Frazer's explanation of 

 the myth ; Thor, Helgi, and Sigurd — a splendid 

 feast of poetry and romance. 



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 for 

 this or any other part of Nature. No notice is 

 taken of anonymous communications.] 



Further Researches into Induced Cell Reproduction and 



Cancer, 



The reviewer ol" i\h-. li. C. Ross's book, "Further 

 Researches into Induced Cell Reproduction and 

 Cancer," vol. ii. (Nature, August 15, page 6oi), 

 appears to mo to have been very unfortunate in saying 

 that "The accuracy of the observations now described 

 depends upon the accuracy of those described before, 

 nnd I hey in turn depend upon the accuracy of an 

 NO. 2239, VOL. 90] 



equation in which degrees of temperature, minutes 

 of time, and cubic centimetres of solutions are added 

 together." The accuracy of Mr. Ross's observations 

 does not depend in any way upon the equation referred 

 to, which is simply a formula for making a certain 

 jelly. The reviewer would imply that the equation 

 itself is unscientific because degrees of temperature, 

 minutes of time and cubic centimetres of solutions are 

 added together, and that therefore the author does not 

 possess even an elementarv knowledge of the subject. 

 The reviewer, however, is himself obviously ignorant 

 of the fact that such an addition is quite scientific 

 and allowable. It is not degrees of temperature and 

 minutes of time which are added together, but the 

 numbers of units of these entities concerned. He 

 might as well criticise any chemical formula, such as 

 H2O, because such would imply that the hydrogen 

 is multiplied by the oxygen. As a matter of fact, 

 Mr. H. C. Ross's equation was given on my advice, 

 because it is the most suitable way of representing 

 the various factors concerned in the proper concoction 

 of the jelly. The equation represents the differential 

 coefficient of a function of many independent vari- 

 ables, which is the sum of the partial differential 

 coefficients obtained from each variable. 



The other remarks of the reviewer show the same 

 want of accuracy. Mr. Ross has proved that human 

 leucocytes can be forced to divide in large numbers by 

 certain agencies, as described by me in Nature of 

 December 14, 1911, No. 2198, p. 231, and it seems 

 to me absurd to maintain that the facts found by him 

 " necessitate the abandonment of every generally 

 accepted belief w-ith regard to mitosis." If the mode 

 of division of human blood leucocytes had been pre- 

 viously determined with certainty, your reviewer's 

 remarks might have been justified ; but this is not 

 the case. If Mr. Ross's observations cannot be recon- 

 ciled with previous hypotheses (which I do not admit), 

 so much the worse for the hypotheses. At all events 

 the leucocytes actually do divide exactly as he has 

 described. 



During the last two and a half years Mr. Ross 

 has been subjected to many criticisms of this nature — 

 which criticisms remind me very strongly of the story 

 of Galileo and his critics regarding the satellites of 

 Jupiter. So far as I remember, it is said that the 

 critics denied the possibility of Jupiter having satellites, 

 but at the same time refused to look at them through 

 Galileo's telescope. I think that if some of Mr. 

 Ross's critics would spend as much time over his 

 specimens as I have done they would not be so free 

 with their a priori objections. Ronald Ross. 



Johnston Tropical Laboratory, University of 

 Liverpool, .\ugust 31. 



A Flower-sanctuary. 



I BEG to thank Mr. Perrycoste for his letter in 

 Nature of September 19. The county of Somerset 

 has for some time had a by-law similar to that of 

 the county of Cornwall ; but you will observe that the 

 bv-Iaw docs not justify the protection of any particular 

 plant, and that the special flora of Cheddar might 

 easily disappear without any violation of its provisions. 

 It only applies to the uprooting or destruction of 

 plants "in such a manner and in such quantities as 

 to damage or disfigure any road," &c., and it is 

 further limited bv the proviso which enables persons to 

 collect specimens in small quantities for private and 

 scientific use. I fear that the cases in which a prose- 

 cution under such a by-law would succeed are very 

 few, and certainly the bv-law falls far short of the 

 realisation of the wish to protect a rare flora. 



Edw. Fry. 



Fairland, near Bristol, September 21. 



