T904. Reviews. 65 



USE-INHERITANCE. 



The Direction of Hair in Animals and Man. By Walter 

 KiDD, M.D. London : A. & C. Black, 1903. Pp. 154. Price 5^. net. 

 In this work Dr. Kidd deals more extensively with an interesting and 

 suggestive, though somewhat neglected subject, than in the little book 

 on "Use-Inheritance," reviewed in these pages two years ago {Irish 

 Nat., vol. X., p. 252). He seeks, to quote his own words, " to co-ordinate 

 the scattered facts of the direction of the hair in the lower animals and 

 man, to furnish interpretations of most of them on mechanical prin- 

 ciples, and to supply an answer to the question, ' Can acquired 

 characters be inherited ? ' " He shows that whorls, featherings, and 

 crests of hair are produced in the skin lying " over a region where 

 strong, very frequent, divergent muscular action prevails," while points of 

 contact with the ground or other opposing surfaces produce " reversed 

 areas" of hair: As an example of the latter contention, it is stated that 

 such a "reversed area of hair on the extensor surface of the ulna is 

 only found in those members of these groups [Primates, Carnivora, and 

 Ungulata] which have the habit of resting this surface against some 

 supporting object." On the same mechanical principles, ** the connec- 

 tion of tropical rain with the peculiar thatch-like slope on the extensor 

 surface of the fore-arm [in many Primates] would be that the rain tends 

 to produce the slope, and not that the slope is produced or adapted for 

 the purpose of running off the rain." Much attention is paid to the 

 differences in the directions of the hair streams on Man and his nearest 

 allies the Apes, and evidence is brought forward to show how these 

 differences can be accounted for by differences in posture and habit. 

 While it cannot be claimed that Dr. Kidd has proved the power of the 

 Lamarckian factor in evolution, he has at least made it easier to believe 

 that some points in animal structure may be due to its influence. 



G. H. C. 



INSECT MIGRATION. 



The Wligration and Dispersal of Insects. By J. W. Tutt, F.E S. 

 London : Elliott Stock, 1903. Pp. 132. Price 55-. net. 

 Everyone has heard or read of the migration of birds, but the migra- 

 tion of insects is a less familiar subject. Strictly speaking, the two are 

 not comparable, since among insects "migration" is not a series of 

 regularly recurring journeys to and from breeding-haunts, but the 

 travels of individuals or flocks, often over large areas, to find new 

 regions in which to live and settle. In this small (and seemingly ex- 

 pensive) but closely printed book, Mr. Tutt has laid entomologists 

 under a deep obligation by compiling from his own observations, and 

 from numerous published sources, a mass of detailed information on thig 

 interesting question. While Hemiptera, Orthoptera, and Odonata are 

 not neglected, the larger portion of the book, by far, is devoted to the 

 migratory movements of the Lepidoptera. Species of especial interest 

 in this connection are the European Pyrameis cardtii and the American 



