ART. 1 GROWTH OF THE FOOT OF MEGAPODIUS FRIEDMANN S 



generally than does Gallus and slightly more than in Tinamus; they 

 show less postnatal development of the tarsus than in either of the 

 latter two. To put it another way : The young megapode, on hatch- 

 ing, has a rather unusually strong, well-developed tarsus, but not 

 particularly large or heavily built toes or claws relative to its size as 

 compared with adult birds. It has larger claws at all stages than do 

 the pheasants or tinamous. The inference to be drawn from these 

 few data (it is hoped they will be greatly extended by others with 

 more abundant material) seems to be as follows: Adult megapodes 

 are built for digging and excavating with their feet ; young ones are 

 not structurally adapted to digging themselves out except in having 

 the tarsus unusually large. In other words, the digging is a matter 

 of the tarsus in the young, while in the adults it seems to be more a 

 matter of toes and claws. The mechanical advantage is greatly in 

 favor of the adults. 



This appears to be correlated with the difference in the sort of dig- 

 ging the young and old birds have to do. In digging down from 

 the surface the old birds can scratch and shovel away the dirt, ash, 

 or sand in all directions, and in such digging large, strong toes with 

 big, heavy claws are of great service. The young birds, however, 

 interred in the ash, sand, or mound, have to dig their way out ; here 

 the type of digging is more like an upward boring without the wide 

 lateral spread possible in the adults' digging. For this type of work 

 large toes with long, strong claws would be more of a hindrance than 

 a help. The final conclusion to be drawn from the meager data 

 available is that the premature development of the tarsus in the 

 young bird up to the point of hatching is a feature that may readily 

 be correlated with the peculiar breeding habits of the megapodes. 



I have dissected the legs of young and old megapodes and find 

 there is no diiference in the arrangement or relative strength of the 

 tendons and muscles working the toes. 



The suggestion that the manner in which the young megapode 

 digs itself out is like an upward boring is substantiated indirectly 

 by Ashby's notes on the Australian megapode Leipoa ocelUta? 



He writes of a newly hatched chick as follows : 



It had hatched out and alter being dried by the hot sand surrounding it, 

 had scrambled up through the mound ; by the mark where it had emerged the 

 course taken was ahnost perpendicular. 



Inasmuch as MegopodiiLS pritchardi is confined to the small and 

 seldom visited island of Niuafou and has been collected only a few 

 times, little has been recorded of it. It is one of the species that 

 buries its eggs in the sand and volcanic ash and does not make laro-e 



^'Auk, vol. 46, pp. 299, 300, 1929. 



