38 Presidential Address. 



'Capturing prey for her young, who remain long in the nest. The 

 superior size and strength here, in fact, are," he suggests, 

 /"related to hunting rather than to fighting. "^ As regards this 

 'recognised disparity in size, we have a word coined by the 

 falconers tiercel, tarsel, or tassel, which is applied to the male 

 of many birds of prey, and " commonly thought tQ signify that a 

 hawk of that sex was a third part less than the female.'"* 

 Although superior in size, I should not describe their plumage as 

 superior to that of the males, the beauty and delicacy of the 

 imarkings of the feathers of the male having, to my eye at least, 

 the advantage. In these two families the superiority in size of 

 the female does not upset the routine we at first described, and 

 we find the female duly hatching her eggs, and both parents 

 assiduously looking after the future welfare of their progeny. 

 Before speaking of another, and distinct famih , it may be well to 

 point out that in the Vulturidre (Vultures) so closely allied, one 

 would think, to the foregoing, the male is larger than the female. 

 In the order Columbae (Pigeons), both sexes take part in the 

 building of the nest, the incubation of the eggs, and the feeding 

 oi the young. I quote from Professor Patrick Geddes and J. 

 Arthur Thomson's book, "The Evolution of Sex." "Everyone 

 has at least heard of Pigeon's milk, and many are familiar with its 

 administration to the young birds. It is produced by both sexes, 

 especially just after the hatching of the young, and is the result 

 of a degeneration of the cells lining the crop. Some of the cells 

 'break up, others are discharged bodily. The re.sult forms a 

 milky emulsion -like fluid, which is regurgitated by the parents 

 into the mouths of the young birds. A similar substance is said 

 to occur in some Parrots."^ In the Gallinae (Game-birds), the 

 natural rule, as we may term it, of the male being the " pre- 

 dominant partner " is followed, with the exception of the Quails. 

 In this sub-family the females are superior to the males in both 

 isize and plumage. In the breeding season thev fight furiously 

 (for the possession of the males. These latter alone sit upon the 

 eggs, and tend the young brood, the females meanwhile sparring 

 and fighting without any thought for their subservient mates. We 

 read that " among mammals and birds the males are in most cases 

 the larger, the same is true of lizards " (where, by the by, the 

 females do not incubate their eggs), " but in snakes the females 

 preponderate. In fishes the males are on an average smaller, 



