178 George B. Wislocki 



maximal in the tines and declined toward the antler base. 

 Another deer with mature, dead antlers which had shed the 

 velvet, was given radioactive phosphorus. The radiogram 

 showed no activity whatsoever in the antler, but some 

 deposition of phosphorus in the pedicle, which ceased abruptly 

 at the line of union with the antler. Alkaline phosphatase 

 activity in Virginia deer as measured biochemically, shows a 

 similar gradient from the antler tips to base (Aub, 1940). 



The antlers are well innervated by branches of the trigeminal 

 nerves (Wislocki and Singer, 1946). Numerous small nerves, 

 located in the vascular layer of the velvet, extend outward to 

 the growing antler tips. The dermis of the antlers is supplied 

 with sensory endings for touch or pain. One antler was 

 denervated experimentally in each of two deer just as growth 

 had started. The denervated antlers grew, but became some- 

 what dwarfed and deformed compared with the normal 

 antlers; they lost their velvet in normal fashion and were 

 ultimately shed. We attributed the somewhat irregular and 

 retarded growth of the denervated antlers to traumatic 

 injury attendant upon loss of their sensory receptors rather 

 than to a loss of a direct trophic influence upon growth. 



The nerves supplying the antlers are probably collaterals 

 which grow out from fibres normally innervating the antler 

 pedicles. The fibres supplying the antlers are destroyed 

 annually when the velvet is lost, but they regenerate seven 

 months later upon renewal of the antlers. In the largest 

 species of deer (elk, caribou), the rate of growth of the nerve 

 fibres must exceed half an inch a day, establishing a record for 

 the rate of growth of nerves. 



More recent observations indicate that, after the velvet is 

 shed, the proximal portions of the nerve fascicles remain dor- 

 mant over winter in the skin of the pedicles until they regene- 

 rate in the following year (Wislocki and Waldo, 1953). In the 

 dermis, close to the distal edge of the pedicle during the period 

 of dormancy, sizable nerve fascicles are encountered, each 

 of which is enclosed in a heavy sheath of epineurium. The 

 suggestion is offered that these heavy sheaths protect and 



