D'Arcy Thompson (1942) described the form of antlers as having developed in a two-dimensional pattern which, during growth, may have become more or less distorted depending on the species. In some (e.g. moose, fallow deer), the antlers may exhibit a palmate configuration; in most deer, however, they are branched structures formed by the repeated two-dimensional bifurcation of the original outgrowth. This process gives rise to a series of tines which vary in number according to age and species. In the sika deer, the first set of antlers, produced in yearlings, are unbranched spikes which may grow as much as 6 inches in length. The following year, these are replaced by branched antlers usually having three points each. Mature bucks ordinarily possess 4 points per antler.
The annual growth cycle of antlers has been thoroughly documented by Waldo & Wislocki (1951), and Wislocki (1956) in the Virginia deer. In the sika deer it is briefly as follows.