THE EVOLUTION OF PATTERNS OF HAIR 



51 



i* 



This hypothetical treatment, with addition of some metaphors, 

 does not carry us far enough to leave it thus to the tender mercy 

 of that class of critic who relies too much on the "'argument from 

 ignorance." He tells us such a process as I have pictured may 

 be true or not, and that no one 

 can do more than leave the case 

 open, and treat it like that of 

 Jarndyce & Jarndyce where it 

 would remain in Chancery till all 

 of us concerned in the inquiry 

 have returned to our dust. The 

 critic might reasonably ask for 

 experiments which will bear out 

 the suggested views. But verifi- 

 cation by calculated experiments 

 is impossible, for, ex hypothesi, the 

 variations or patterns which are 

 described require long periods of 

 time for their production. Such 

 experiments being ruled out, the 

 evidence in favour of the hypo- 

 thesis must be sought in some 

 region of the hairy coat of 

 mammals where whorls, feather- 

 ings and crests can be observed 

 in all stages of their formation. 



The Side of the Horse's Neck. 



The field chosen for observa- 

 tion is, from one point of view, 

 the most remarkable among all 

 the numerous regions in the great 

 series of hair-clad mammals. The 

 side of the neck in the domestic 

 horse displays all degrees and 

 forms of whorls, featherings and 

 crests in such variety as to be 

 almost bewildering. I must have 

 examined many thousands of specimens of this valuable large 

 mammal in reference to this state of things on the side of its neck, 

 and can only regret that I have not kept any record of them as to 

 number or quality, and I fear the opportunity for doing so will 

 not return in this country. There are three reasons for this choice 



e2 



Fig. 2. — A. Diagram of a whorl. 

 B. Diagram of a whorl (w) 

 a feathering (f) a crest (c). 



