172 ACQUIRED CHARACTERS sec. 



ment, and generally when in a mentally depressed condition, 

 or even draws it in tightly between his legs, while during 

 the feelings of security, pride, or conquest he elevates it. 

 Must not, then, the feeling of security, which the dog as a 

 domesticated animal almost always possesses to a much 

 greater degree than his wild ancestors, have gradually pro- 

 duced the habit of constantly carrying the tail erect ? I 

 know not of course how wolves and jackals carry the tail when 

 specially well pleased — they may possibly then elevate it 

 somewhat. Of the fox, however, apparently in contradiction 

 to my interpretation, it is known that he raises his standard 

 in flight ; but this may be an expression of the consciousness 

 the animal has of mental power, or it may be merely a conse- 

 quence of a high degree of excitement, in which condition 

 dogs too, e.g. when fighting, or in the case of the pointer when 

 pointing, raise their tails. 



I will add here another hypothesis similar to that of the 

 origin of horns. It seems to me that the combs and wattles of 

 our domestic fowls are to be ascribed to similar causes. The 

 originals of tliese fowls in India (Gallus bankiva) have these 

 appendages only slightly developed. It is known to every 

 keeper of fowls how much they fight, especially in confined 

 enclosures, pecking at each other's heads and combs, not to 

 mention the similar habit of the cock in treading. In a 

 free condition, the hens probably contrive to ev^ade these 

 attacks, and it seems to me allowable to ascribe the extreme 

 development of the comb in our domestic fowls, although 

 artificial selection has doubtless to be considered, to the 

 constant external stimulus referred to, to find in this stimu- 

 lus the causes of the greater development. The ultimate 

 causes of the commencement of the development may of 

 course in fowls, as with the horns of ruminants, lie in purely 

 physiological internal phenomena of growth. 



