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AT A MEETING OF THE SOCIETY 



HELD ON 



WEDNESDAY, 17th DECEMBER, 1902, 

 DOCTOR WALTER KIDD 



READ A PAPER ON 



"THE HAIR OF ANIMALS VIEWED AS A 

 STREAM." 



The direction taken by the hair of animals was 

 considered, and the facts interpreted by the light of the con- 

 ception of the hair as a stream. 



Taking the doctrine of descent with the modification as 

 a basis, the various divergencies from a primitive type of 

 hair-slope require mechanical and natural explanations. 

 The term " Hair-stream 5 ' is accepted in anatomical descrip- 

 tions, and the idea of a slowly-moving stream more nearly 

 represents the facts of the case than any other. 



There would seem to be only two natural explanations 

 of the facts of the direction of hair. First, that these are 

 governed by natural selection, and that they are therefore 

 adaptive modifications. Secondly, that they are modifications 

 produced by the habits or environments, or both, of the 

 animals in question. Certain of the facts were shown to be 

 under the province of natural selection, but most of the 

 modifications were held to be entirely removed from any 

 such influence, and no explanation is forthcoming except the 

 Lamarckian view of acquired characters. If this be so, 

 Weismann's theory of heredity breaks down. Certain main 

 regions of departure from a primitive type of hair-slope were 

 dealt with, viz. : — Nasal and Frontal regions of the head, 

 Cervical, Spinal, Axillary, Inguinal, Pectoral and Gluteal 



