February 1, 1899.] 



KNOWLEDGE. 



25 



Founded by RICHARD A. PROCTOR. 



LONDON: FEBRUARY 1, 1899. 



CONTENTS. 



of Wild Birds. Bv Chames A. 



E. Stebbiko, 



Unseen Cone. 



(Illustrated) 



On the Treatment and Utilization of Anthropological 

 Data.— I. Colour. By Abthue Thomson, m.a., m.d. 

 {Illustrated) 



The Bad Language 



"WlTCHELL - ■• -.. ••■ ■■ •■ ■•■ 



The Karkinokosm, or World of Crustacea.— Vll. The 



Box Crustacea. By the Rev. Thomas K. 



M.A., F.B.S., F.L.S., F.z.s. (Illustrated) 

 Secrets of the Earth s Crust.— I. The 



By Gkenville A. J. Cole, ii.R i.A., 

 Notices of Books 



Books Rkceited 



Science Notes 



Obituary 



Letters : A. C. D. Crommelin; C. E. Martin ; Walter E. 



Beslet; Howard B. Little; W. H. S. Monck 



The November Meteors in 1898 



Photograph of the Nebula N. G. C. No. 1499 Persei. 



By Isaac Egberts, d.sc, p. e.s. (Flate) 



Comparative Photographic Spectra of the Brightest 



Stars 



British Ornithological Notes. Conducted by Habet F. 



Witheebt, f.z.s., m.b.o.u 



The Nervous System of our Empire. By John Mills 

 The Icknield Way in Norfolk and SufTolk, By W. G. 



Clarke. (Illustruted) 



Microscopy. By John H. Cooke, f.l.s., p.a.s. 



Notes on Comets and Meteors. By W. F. Dennin&, 



F.R.A.S. ... 



The Face of the Sky for February. By A. Fowlee, 



F.R.A.S. {Illustrated)... 

 Chess Column. By C. D. LocoCK, b.a. 



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41 

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47 

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ON THE TREATMENT AND UTILIZATION OF 

 ANTHROPOLOGICAL DATA. 



By Arthur Thomson, m.a., m.d. 

 I.- COLOUR. 



ONE of the most interesting, as well as one of the 

 most difficult, problems with which we are brought 

 face to face in the study of man is the question of 

 colour. At first sight nothing makes so strong an 

 impression on us as the distinctive colours of the 

 races with which we are brought in contact. Hardly any 

 other subject within the domains of physical anthropology 

 has attracted so much attention, yet in spite of many 

 ingenious theories and speculations as to its origin and the 

 mode of its production, we are confessedly very ignorant 

 of its true nature and significance. WbUst some would 

 have us believe that primitive man was fair complexioned, 

 there seems no less cogent reasons for maintaining that 

 his skin was of a darker tint. It is not necessary for us 

 to accept the extreme position, and thereby assume that 

 he was black. A middle course is open, as suggested by 

 Dr. A. R. Wallace, who advances the view that primi- 

 tive man was probably of mongoloid stock, and that his 



subsequent modification into the white, and brown, and 

 black varieties was due to his migrations into geographical 

 areas, where he was subjected to the influence of varied 

 conditions and climates. Whilst not committing ourselves 

 to the acceptance of any such opinion with regard to the 

 colour of our primitive stock, the theory propounded is 

 suggestive, because it implies that colouration in man 

 depends on the disposition of a common pigment or 

 pigments in varying amount, and enables us to reahse that 

 the transition from fair to dark is a gradual one, and 

 therefore possibly produced by the organism reacting to the 

 influence of its environment. Throughout the hterature 

 of the subject there are a vast number of so-called facts, 

 but imfortunately in many instances the information 

 suppUed is rendered valueless because insufiicient_ data 

 have been supplied to enable us to form a correct estimate 

 of, or draw definite conclusions from, these observations. 



Our intention in the present article is rather to draw 

 attention to those associated details which seem to us 

 of importance in studying the question, rather than to 

 enter into a discussion of the theories advanced to account 

 for the presence or absence of pigment in the skin of man. 

 Before doing so, however, it may be well to state briefly 

 what is known of the anatomical distribution of this 

 pigment. Confining our attention more or less to its 

 presence in the skin, we must refer shortly to the structure 

 of the integument. 



The cutis rera, or true skin, of mesoblastic origin, 

 is a felted layer, of more or less compact tissue, 

 abundantly provided with vessels and nerves. Superposed 

 on this, and filling up the many irregularities of its surface, 

 is an epithelial layer of epiblastic origin — the epidermis, 

 cuticle, or scarf skin. The thickness of this layer varies 

 considerably in different parts of the body, but in all cases 

 we are able to distinguish a difference between the character 

 of its deep and superficial cells. The former are polyhedral, 

 large, and juicy, and are separated from each other by a 

 series of intercellular channels ; this layer constitutes 

 the stratum mucosum of Malj'i;ihi. The character of the 

 superficial ceUs is altogether different ; they are compressed, 

 flattened, dry, and horny, and constitute the stratum 

 conieum. In some situations better than in others, we 

 can see between these two layers an intermediate zone, 

 consisting of a layer of cells of highly granular appearance 

 — the stratum granulosum. Overlying this we find a thin, 

 clear, glassy-looking layer, the stratwii lucidum. Be it noted 

 that the blood vessels do not penetrate into any of the 

 above epidermic layers. If, now, the skin of a negi-o be 

 exammed, the pigment will be found in granular form 

 within the deeper cells of the stratum mucosum, more 

 abundant in quantity in those cells which rest on the 

 surface of the cutis rent, and gradually diminishing in 

 amount as we pass fi'om the deeper cells to the surface, 

 until at length it disappears altogether, and the superficial 

 layers of the epidermis are left clear and transparent. 



This pigment, of which melanm is an important con- 

 stituent, is a highly complex body, possessing remarkably 

 stable quahties. What we know of its chemical constitution 

 we owe largely to the researches of Sorby, whose mono- 

 graphs on the subject still remain the standard authority. 

 That observer conducted his investigations on the pigment 

 of hair, which for all practical purposes may probably be 

 considered as identical with that of skin. He was able to 

 isolate three pigments, a brown-red, a yellow, and a black 

 constituent. In the lighter tints of hair the two former 

 colours or admixtures of them are alone met with. When the 

 shade grows deeper, it is due to the addition of the black 

 constituent in variable quantity. In absolutely black hair, 

 however, after the black pigment has been separated out, a 



