574 DBS. GEOEGE AND EEANCES E. HOGGAN ON 



"Without passing to animals lower in the scale than mammals, 

 we have every reason to suppose that the touch-corpuscles, or 

 corpuscles of Meissner, on the smooth surface of the fingers and 

 toes of man and of many of the lower animals, are also representa- 

 tives of modification of the nerve-terminal apparatus belonging 

 to hairs. Unlike, however, the organ of Eimer, the touch-cor- 

 puscles, to our minds, represent an aborted condition of the hair- 

 nerve apparatus, the hair-nerves having originally developed and 

 become modified as in the case of the organ of Eimer ; and we 

 are only surprised that no one has noticed even the probability 

 of this origin for the touch-corpuscles. 



It is not our intention to enter further into the question of 

 the homology of the touch- corpuscle with the hair-follicle and its 

 nerves at present ; but any one who has studied the development 

 of these corpuscles in the infant cannot fail to recognize in the 

 disk-like expansion and elongated thickenings on its nerves the 

 elements we have described in the hair-foUicle. That the group 

 of nerve-endings forming the touch-corpuscle never enter the 

 epidermis, is probably accounted for by the development of the 

 hair, or rather of the connective-nodule part of it. 



Leaving out of consideration the fibrils of the inner circle, the 

 homologues of the forked endings on the hair-follicles, which do 

 not appear to be represented at all on the hairless portions of the 

 skin, all the other elements of the organ of Eimer have their 

 homologues in that portion of the sldn where they exist under 

 conditions which give indications as to function and direction of 

 growth that we look for in vain either upon the hairs or the 

 organ of Eimer. We even think that it is unfortunate that others 

 should have made of that organ the test or foundation upon which 

 an important hypothesis as to the direction of growth of intra- 

 epidermic nerves should have been founded. Erom what we have 

 already said, it must have been abundantly evident that the 

 nerve-arrangement in the organ is an abnormal one, more espe- 

 cially the inner circle of fibrils, which represents structures 

 nowhere else found within tlie epidermis, or any other part of 

 the animal-body that we are aware of. Yet it is precisely upon 

 the crumbling away of the superficial or peripheral points or 

 buds of that portion, that Ranvier rests his hypothesis of the 

 direction of growth of intraepidermic nerves. 



The Tail of the Mole as a special Tactile Organ. 

 Before passing from the consideration of the nerve-arrange- 



