EXPERIMENTAL 137 



surfaces, as can be learned from careful watching of the motion of a 

 horse. 



Another reason which meets this objection very fully is that 

 I have shown that 300 cart horses presented 277 of their number 

 with reversed areas of patterns in the middle line of the under 

 surface of the neck and these thick -necked animals are just those 

 in which the collar is closely applied to the front of the neck in 

 their heavy draught work, thus rubbing almost incessantly against 

 the lie of the hair. In the thinner necks of the hackneys there 

 are comparatively few indeed of the patterns found here and their 

 collars as a rule fit very loosely and badly, and these frequently 

 show a jolting up and down clear of the neck, which is seldom if 

 ever present in a well -formed cart horse. 



Further proof of this is shown by the simple fact that it is 

 under the collar and within its range of movement that the changes of 

 hair are produced. 



No artificial pressure such as that of a collar is exerted on 

 the parts of the side of the reck where the patterns are found ; so 

 I would submit that these two selected and much -disturbed areas 

 owe their hair-patterns to two wholh r different forms of mechanical 

 cause. 



I referred in the Preface to an important criticism of my 

 earlier book on The Direction of Hair in Animals and Man, and will 

 now treat this in some degree of detail. It is from the pen of an 

 eminent American biologist, then Miss Ir ez L. Whipple, 1 now Mrs. 

 Wilder Harris, and it is a careful, independent and thoughtful 

 contribution from one who by her studies in this field and in the 

 study of the mammalian palm and sole is widely known, and as 

 widely respected. 



Miss Whipple refers on page 403 to certain whorls and feather- 

 ings on the backs of the lion, ox, giraffe and larger antelopes, 

 which I then attributed to the action of the panniculus carnosus 

 in shaking off flies. I am free to confess that the action then 

 invoked by me was inadequate and incorrect and the explanations 

 now given of them in Chapters X. and XI. on the ox and the lion, 

 I think, are less open to criticism. 



Again on page 404 she mentions the view formerly expressed 

 as to the cause of the reversal of hair on the chest of man. This, 

 also, I have reconsidered fully in Chapter XIII. where the action of 

 the platysma muscle is held to be the cause of that remarkable 

 reversal . 



On page 403 the mistake I made in calling the reversed area 



1 Science, 23rd September, 1904. New York. 



