894 THE SHAPES OF HORNS [ch. 



of a plate. The important point for us is to recognise that 

 (save for occasional slight irregularities) the branching system in 

 the one conforms essentially to the curved plate or surface which we 

 see plainly in the other. In short the arrangement of the branches 

 is more or less comparable to that of the veins in a leaf, or to that of 

 the blood-vessels as they course over the curved surface of an organ. 

 It is a process of ramification, not, like that of a tree, in various 

 planes, but strictly limited to a single surface. And just as the 

 veins within a leaf are not necessarily confined (as they happen to 



Fig. 439. Head and antlers of the Indian swamp-deer (Cervus Duvaureli). 

 After Lydekker, from P.Z.S. 



be in most ordinary leaves) to a plane surface, but, as in the petal 

 of a tulip or the capsule of a poppy, may have to run their course 

 within a curved surface, so does the analogy of the leaf lead us 

 directly to the mode of branching which is characteristic of the antler. 

 The surface to which the branches of the antler tend to be confined 

 is a more or less spheroidal, or occasionally an ellipsoidal one; and 

 furthermore, when we inspect any well-developed pair of antlers, 

 such as those of a red deer, a sambur or a wapiti, we have no difficulty 

 in seeing that the two antlers make up between tliem a single surface, 



