Nov. 



21, 



1889] 



NA TURE 



53 



A Life of John Davis. By Clements R. Markham, C.B., 

 F.R.S. (London: George Philip and Son, 1889.) 



This is the first volume of what promises to be a series 

 of great value and interest. The object of the series, as 

 explained by the editors, is to provide a biographical 

 history of geographical discovery. Each of the great 

 men who " have dared to force their way into the un- 

 known, and so unveiled to us the face of mother earth," 

 will form the subject of a volume ; and an attempt will be 

 made, not only to present a vivid picture of the character 

 and adventures of these heroes, but to estimate exactly 

 the scientific value of their work. If the scheme is carried 

 out in a manner worthy of the stirring tales to which it 

 relates, the series will be a source of much wholesome 

 pleasure to all who care to understand how our present 

 knowledge of the earth's surface came to be built up, and 

 who are capable of appreciating the splendid qualities, 

 moral and intellectual, of all who have won for them- 

 selves a place in the list of illustrious explorers. The 

 subject of the present volume could not have been in- 

 trusted to a more suitable writer than Mr. Clements 

 Markham. He tells in a simple and natural style the 

 tale of Uavis's life, displaying at every stage of the story 

 full and accurate knowledge, and summing up clearly the 

 achievements which entitle the discoverer of Davis 

 Straits to be ranked " among the foremost sea-worthies 

 of the glorious reign of Queen Elizabeth." Two admirable 

 chapters are devoted to the following-up of the work of 

 Davis, and in an appendix the author gives all necessary 

 information as to authorities. Mr. Markham has done 

 his work well, and it will be no easy task for the writers 

 of the succeeding volumes to maintain the series at the 

 same high level. 



The Brook and its Banks. By the Rev. J. G. Wood. 

 (London : The Religious Tract Society, 1889.) 



The Zoo. Second Series. By the Rev. J. G. Wood, 

 (London : Society for Promoting Christian Knowledge, 

 1889.) 



The first of these two books was written for the Girls' 

 Own Paper, and a few chapters of it have been printed 

 in that periodical. Now the complete work is issued 

 separately, and it will no doubt be welcomed by many 

 readers who have already profited by the late author's 

 well-known writings. The reader is supposed to be con- 

 ducted along the banks of an English brook, and to learn, 

 as he advances, the characteristics of the living creatures 

 which are to be found by the way. The idea is carried 

 out brightly, and — we need scarcely say — with ample 

 knowledge. There are many illustrations, and they add 

 considerably to the interest of the text. 



" The Zoo " contains an account of animals of the 

 weasel tribe, the seal tribe, the rodent family, and various 

 kinds of oxen. The descriptions are clear, compact, and 

 lively, and cannot fail to interest the young readers 

 for whose benefit the book was originally planned. 

 Mr. Harrison Weir contributes a number of excellent 

 illustrations. 



LETTERS TO THE EDITOR. 



\The Editor does not hold himself responsible for opinions ex- 

 pressed 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, "l 



Protective Coloration of Eggs. 



The following letter records a very interesting observation 



which is new to me, and I should be glad to hear if any similar 



• fact has been noted l.efore. If not, it would be very interesting 



if those who have the opportunity would, in the coming spring, 

 seek for as many nests as possible of the red-backed shrike, and 

 see if they can find any correlation between the colours of the 

 eggs and the lining material of the nest. 



Parkstone, November i. Alfred R. Wallace. 



" Merchant Taylors^ School, Crosby, Liverpool, 

 " October 15, 1889. 



" Dear Sir, — I wish to bring before your notice an observa- 

 tion of mine relative to the purpose of colour in animals. 



" The red-backed shrike {Lanius collurio). Colour of eggs — ■ 

 either pale blue or green, white ground with zone of spots at 

 larger end ; or, pink ground -^'wh. reddish spots. 



" Observation. — The colour of the lining substance of the 

 nest— such as roots — assimilates to the colour of the eggs, being 

 dirty gray material when the eggs are to be pale (blue or green) 

 white, but being of red-brown roots, &c., when the eggs are to 

 be pink. 



" Evidence for above statement. About sixteen years ago I 

 was a lad of fifteen, an enthusiastic birds'-nester, living at Maid- 

 stone, and found several (I forget how many) nests, and noticed 

 this ; and it so puzzled me — because I could not make out how 

 the bird knew what coloured lining to select, because she made 

 her nest before she laid her eggs — that I have never forgotten it. 

 In those days I had never heard of ' The Origin of Species,' 

 nor did I trouble myself about evolutionary theories, knowing 

 nothing about them, so that there was x\o predisposing cause in 

 me to make a wrong observation. Yet I remember it was only 

 a school-boy's observation, and therefore it needs confirmation. 



" Assume the fact. Protective, obviously. Yet, how does the 

 bird know ? We know birds build nests from observing other 

 nests, and not by instinct wholly. 



" [a) Have we here incipient species, in which the young, 

 emerging from pink eggs, remember their own infancy in a red- 

 dish nest ? 



'^ [b) Has the sight of the red lining an influence over the 

 mother to tinge the eggs pink — i.e. would a shrike brought up 

 in ^ pink cage be more likely to lay pink eggs ? or a gray rabbit 

 in a black or white hutch have a greater proportion of black or 

 white variants in her litter ? 



" (^) A mere coincidence ; too few observations. 



"Will you forgive one who intends to be amongst your au- 

 dience on October 29 and 30, if not prevented, thus trespassing 

 on your time — time which, spent in research, is so valuable to 

 the whole scientific world ? Yet, I do think my boyhood's obser- 

 vation is worth recording, if only to direct other observers. 



"E.g. has the amount of white quartzite veins in a cliif, or 

 chalk, any influence in the percentage of white, as against blue, 

 eggs of the common guillemot ? 



" Believe me, yours faithfully, 



"(Rev.) Fred. F. Grensted." 



Science and the India Civil Service Examinations. 



The position of science candidates in the Civil Service com- 

 petitions is largely in the hands of the science examiners. In 

 some cases they have practically struck their subject out of the 

 schedule by requiring, or by acquiescing in, the demand for a 

 standard of knowledge far beyond the proportion of marks as- 

 signed. Even in the last India Civil Service competition the 

 first two men in chemistry only scored 196 and 195 respectively, 

 whilst the first two in German, out of the same maximum, 

 gained 359 and 353. If the eminent men of science who un- 

 dertake these examinations would see that science had fair play, 

 many more candidates would be encouraged to study it. What- 

 ever the private views of the Civil Service Commissioners may be, 

 their absolute justice and honourable impartiality are unassailable. 

 Even if they did not altogether concur in the opinions of the 

 examiners, they would give their arguments careful consideration, 

 and see that all interests should be duly regarded. 



It will not advance the claims of science to weight them with 

 the very doubtful proposition that " the Universities of England 

 and India" are the only places where "well educated" men are 

 to be found. Many most distinguished men of science have not 

 had the advantage of a University degree in early life. No 

 one would venture to class them for this reason in "an inferior 

 order of men." Henry Palin Gurney. 



2 Powis Square, W., November 15. 



