110 BRITISH BIRDS. [vol. vii. 



the first egg at once, so that it hatches two days before 

 the other. When one day old the first young one leaves 

 the nest, and is imniediately taken charge of by the 

 male, who finds all food and broods it most carefully. 

 When the second is strong enough to leave the nest 

 the mother takes charge of it. 



Also of the Siberian Crane it is stated that two eggs 

 are laid, and, as is the case with the former species, 

 the male incubates until the laying of the second egg. 



Bearing this evidence of the birds being ovitegous 

 in mind, the following quotation from Blyth's Monograph 

 of the Cranes is of considerable interest : — 



As a rule two eggs are produced, but Mr. Hume remarks of the 

 Siberian Crane (as observed by him in its winter quarters) that " they 

 never appear to have more than one young one with them ; but it 

 does not at all follow," he adds, " that they do not lay more than one 

 egg. Our commonest Indian Crane (G. antigone) which usually lays 

 two, and sometimes, though rarely, three eggs, and which has no long 

 and arduous jovirney to perform, seldom succeeds iii rearing more 

 than a single young one." He further adds that, of more than a 

 hundred pairs of Siberian Cranes which he had observed in their 

 winter quarters, he had not seen any accompanied by more than a 

 single offspring. 



Mr. F. M. Chapman, in his Camps and Cruises of an 

 Ornithologist, places some very interesting information 

 on record, which bears directly upon the subject discussed 

 in this article. 



On Cay Verde he found thirty-five nests of Boobies 

 (Sula leucogaster) containing eggs. Of these twenty-one 

 held two eggs, while fourteen contained one only, but 

 possibly in some, if not most of these, another egg 

 would have been laid. Two eggs, therefore, was the 

 rule, which confirms previously recorded observations 

 on the nesting-habits of this species. On the other 

 hand, two young were the exception. Of seven hundred 

 and forty nests counted by Dr. Mayer, on the east side 

 of the Cay, only two contained two young, and both 

 pairs were well grown and approximately of the same 

 age. On examining the eggs found in sets of two, it 

 was discovered that either there was a marked difference 

 in the development of the embryos, or that one or both 



