64 ANNALS OF SCOTTISH NATURAL HISTORY 



Mammals, and a popular work, at a popular price, and with coloured 

 illustrations was certainly a desideratum. The book under consider- 

 ation aims at supplying this want, and does so with partial success. 

 A great deal of useful information is afforded about a large number 

 of species, and on the families and orders to which they belong ; 

 but the author has not, we think, treated his subject as attractively 

 as he might have done. The chapter on Structure is rather too 

 technical to be in consonance with the elementary aim of the 

 volume. The coloured plates, each of which figures several species, 

 must be considered satisfactory, when the very reasonable price of 

 the book, which is very nicely got up, is borne in mind. 



THE SENSE OF TOUCH IN MAMMALS AND BIRDS, WITH SPECIAL 

 REFERENCE TO THE PAPILLARY RIDGES. Walter Kidd, M.D., F.Z.S. 

 pp. viii+i76. With 164 Illustrations from Drawings and Micro- 

 photographs. London: A. & C. Black, 1907. 53. net. 



The sense of touch is here discussed in relation to the capillary 

 ridges and the papillae of the corium. The mode of treatment is 

 purely anatomical and intended to demonstrate the great variations 

 in the epidermis and corium on the palmar and plantar surfaces. 

 The complexity of the ridge patterns in different regions digital, 

 palmar, and plantar is found to be in close correspondence with 

 the activity and function of the respective parts, a generalisation 

 especially borne out by a comparison of the palm and sole of the 

 baboons with the digits, of the digits of the gibbons with the palm 

 and sole, and of the terminal phalanges of man with any region of 

 any animal. The microscopic studies are concerned only with the 

 outlines of the papillae of the corium and the papillary ridges, the 

 degrees of development of which are closely related. The author 

 shows that the differentiation of these papilla? and ridges increases 

 with the higher development of the species examined, and he holds 

 that, although they certainly serve as aids to the prehensile efficiency 

 of the limb, this is a secondary function, the nature and arrange- 

 ment of the ridges, and the intimate and essential connection of the 

 papillary ridges with the sensory papillae of the corium are more 

 compatible with the view that the ridges primarily subserve the 

 sense of touch. Considerable attention is devoted to the " imbri- 

 cation " of the papillary ridges, an arrangement which increases the 

 discriminative sensibility of the skin, and the nature of the papillary 

 ridging of the foot in relation to its aid in the maintenance of equili- 

 brium is also discussed. 



It is evident that great care has been bestowed upon the observa- 

 tions on which the conclusions are based, and upon the preparation 

 of the figures with which the book is well illustrated. The numer- 

 ous facts would have been rendered more easy of access had an 

 index been provided. 



