552 IHRS. GEORGE AKD TRANCES E. HOGGAK ON 



chloride of gold for microscopical observations, and served for 

 the basis of this paper. 



After, as we thought, discovering the various kinds of nerve-ter- 

 minations upon the hairs on the tail of the Mole, and studying the 

 character of the intraepithelial nerve-fibrils in the "organ of Eimer" 

 and other parts of the hairless portions of the surface of the animal, 

 vs^e, naturally enough, extended our research to the bodies of other 

 members of the Insectivora, such as the Shrew and Hedgehog, 

 in the hope of finding some analogy in them with the organ of 

 Eimer and other nerve-terminations, especially in the noses of these 

 animals. Finally we extended our observation to a large number 

 of other animals of difierent classes, such as Man, the Mouse, Eat, 

 Eabbit, Gruinea-pig, Sheep, Pig, Groat, Bullock, Cat, and Horse ; 

 and this has enabled us to arrive at general conclusions which 

 would have passed unnoticed had we confined our observation 

 to the one class of the Insectivora. In this research, therefore, 

 we shall treat the question in a general way, taking each separate 

 element as a whole, and afterwards pointing out modifications 

 where they exist in different animals. 



Nerve-Distribution upon Hairs. 



There is a widely diffused popular and even scientific belief 

 that in the lower animals one exceptional form of hairs, found 

 on the whiskers, eyebrows, ear-tufts, elbows, &c., and spoken 

 of generally as v^hiskers, feelers, or tactile hairs, alone pos- 

 sesses special tactile nerve-organs, and that they differ in this 

 respect from the ordinary hairs of the rest of the body, which are 

 alone represented in man. Within the last year or two, however, 

 researches have been made which go far to show that even the 

 minutest hairs upon the smallest, as upon the largest, mammals 

 possess a more or less complicated nerve-supply; and it is now 

 considered that as all the hairs on an animal's body are equally 

 supplied by nerves of touch and of general sensation, the term 

 tactile hair, as it applies to all hairs, should be henceforth disused. 

 In lieu of the term tactile, it is proposed to use a term derived 

 from a microscopically minute anatomical difference between 

 feelers and ordinary hairs, which would be unintelligible to most 

 people from its obscure character, and, having no evident bearing 

 on physiological characters, would soon have to be replaced by a 

 more suitable name. To us the term feeler seems, upon both 



