The Growth Cycle of Deer Antlers 181 



the growth stimulus. Thus, growth rather than death of the 

 tissues at the antler-pedicle junction represents the major factor 

 causing the antlers to be shed. The observed proliferation of 

 fibrocellular connective tissue at the antler-pedicle junction 

 which accompanies the resorption of the osseous connections 

 appears to be primarily responsible for the separation of the 

 antlers from their pedicles. Furthermore, the hypothesis 

 was advanced that the proliferation of the dermis surrounding 

 the antler base exerts an upward thrust upon the underside 

 of the flange-like osseous burr, causing the live tissues in the 

 pedicle to disengage from the dead antler, whereupon minor 

 trauma and mere weight of the antlers hasten their final 

 separation. In a less well-documented study, Gruber (1937) 

 advanced a somewhat similar concept of the process of 

 antler-shedding in the roe deer (Capreolus capreolus) and the 

 European stag (Cervus elaphus); nevertheless, Bruhin, as late 

 as 1953, still adheres to the older view that shedding occurs 

 during a period of quiescence or latency. 



The relation of the phases of the antler cycle to seasonal 

 changes in hormone levels in Virginia deer, as elucidated by 

 the studies cited, are illustrated diagrammatically in Fig. 1. 



In 1943, Wislocki pointed out that the growth phase of 

 the antler cycle is initiated and completed in the spring and 

 summer during a period of increasing and maximal daylight, 

 whereas the shedding of the velvet and rutting (increasing 

 gonadal activity) occur in the autumn during a period of 

 diminishing daylight. Experiments were planned at that time 

 to test the possible role of light in regulating the antler cycle, 

 but these were subsequently never carried out. Meanwhile, a 

 single experiment on a red deer (Cervus elaphus) has been 

 reported by Jaczewski (1952). A stag in which antler growth 

 commenced early in March, was confined daily, beginning on 

 April 1, in a dark stall, from 4:00 p.m. to 8:00 a.m. On June 

 11, while still confined, the velvet was shed and the stag 

 became aggressive. He was thereupon released and placed 

 out of doors, and on July 12, shed his antlers. New antlers 

 began immediately to grow and by mid- August had developed 



