10 BIRDS OF NEW ZEALAND. 



the Apteryx, which in the case of that of A. manfelli, as laid in the Zoological 

 Gardens, weighed Hjoz., while the contents w^ere 13i oz., and the living 

 female herself 60 oz., her egg being nearly one fourth the weight of the 

 parent. 



In ' The Ibis ' (3rd ser. vol. iv. July 1874, p. 215), Dr. J. Haast, in his 

 article on the extinct birds of New Zealand, makes mention that " Of 

 Meionornis casuarinus [rectius Mionornis] we have a series of four clearly 

 defined sizes in our possession." The same variation is spoken of in other 

 fossil species. He goes on to observe, " If we compare two skeletons of 

 Apteryx australis, male and female, and two of A. owenii, male and female, 

 wdth each other, a similar distinct gradation is observable." 



In their memoir on the Solitaire, the Didine bird of Rodriguez, Pezophaps 

 solitaria (Gmel.), Professor Newton and his brother Mr. Edward Newton 

 express themselves "much embarrassed by the wealth of their materials." 

 They allude to the extraordinary variation in size. This variation had 

 previously deceived even such experienced persons as Strickland and 

 Mr. Bartlett, and it extended to " the relative proportion of divers parts of 

 the bones." I have observed in various living birds of the same species, for 

 many years past, an extraordinary variation in size. But this subject is 

 too long. 



The defenceless condition of these birds, deprived of any volant power, 

 renders it necessary that the newly hatched young, like all those called by 

 Professor Owen "Aves prsecoces," should run about and provide food for 

 themselves as soon as they leave the shell. At p. 257, vol. ii. of his 'Anatomy 

 of Vertebrates,' he gives the number of davs of incubation in thirty-two 

 species of different orders; they vary from the Wren (^Troglodytes vulgaris), 

 which sits ten days, to the Emu (^Dromaius novce-hollandics), which takes fifty- 

 four. Dr. Buller mentions a female Apteryx in his aviary which for forty 

 days before extrusion of her egg moved with difficulty ; and though the 

 exact time cannot be given, yet it is certain that it is unusually long, perhaps 

 as much so as in any known species. 



