892 SIR V. BROOKE ON THE [Nov. 19, 



hensive fact of the gradual augmentation of complexity in these 

 organs through geological time ; but as the converse, namely the 

 existence of highly complicated antlers in the Miocene and Pliocene 

 periods, finds no support in the Geological record, the simple antlers 

 of some existing species may be, I think, safely regarded as the 

 result of arrestation, dependent on a less severe struggle for existence, 

 or possibly upon some hitherto undiscovered influence. 



(2) A constant tendency to vary. 



Of this, any one can satisfy himself by the inspection of large 

 collections of antlers. No two antlers are ever exactly alike ; and 

 the variations to which the antlers are subject in some species (e. y. 

 Cervus elaphus, vide infr. p. 910) is so great, that in the absence of a 

 large series they would be held as indicative of several distinct species. 



(3) Variation extending far enough to induce the partial atrophy 

 of one part of the antler to compensate for the extra development of 

 some other part. 



To illustrate this subject exhaustively would occupy more space 

 than can be well devoted to it in the present paper. An attentive 

 examination of any large collection will yield abundant evidence that 

 such is invariably the case. It will, perhaps, be sufficient for my 

 present purpose to bring forward one special example. The normal 

 form of the upper half of the antlers of the common Fallow Deer 

 (fig. 9, p. 914) may be described as broadly palmated, with several 

 rudimentary tines produced from the posterior margin of the palm, 

 the tine situated lowest on the palm exceeding the others slightly in 

 length (fig. 9, d). In my cousin Mr. J. Bloomfield's place, Castle 

 Caldwell, on the shores of Lough Erne, there is a herd of Fallow 

 Deer which have lived at large in the woods, and under perfectly 

 natural conditions, for upwards of 50 years. The antlers of these 

 Deer are so remarkable in form, and present the peculiarities in 

 which they are remarkable so constantly, that they could be recog- 

 nized amongst a large collection of Fallow-Deers' antlers without the 

 slightest difficulty. The tine growing from the inferior and pos- 

 terior border of the palm (Plate LV. fig. 3, d) is in the Castle-Cald- 

 well Deer immensely developed, and the palm itself is much con- 

 tracted and seldom bears more than 3 or 4 tines. Variation is still 

 actively at work on the antlers of these Deer, and reversion towards 

 the normal form occasionally asserts itself; but, notwithstanding, a 

 fixed type of antler has stamped itself indelibly upon the males in 

 this herd in the short space of 50 years, and the peculiarities cha- 

 racteristic of that type are unquestionably the result of the extra 

 development of one of the posterior tines and the consequent par- 

 tial atrophy of the palm. 



(4) The transmission and fixation of such variations by heredity. 

 That this is the case has been in a large measure proved by what 



has been already said ; but the following fact places the matter be- 

 yond all possibility of doubt. The Castle-Caldwell Deer are the 

 descendants of about one or two males and twice as many females. 

 A single antler of one of the fathers of the herd has been fortunately 

 preserved in the Museum at Castle Caldwell. This antler (Plate 



