490 A CONTRIBUTION TOWARDS OUR KNOWLEDGE OF 



coverts, which lie on either side of the body like a series of long closely packed 

 camel-hair pencils — the tips of the feathers having already burst the investing sheath 

 in which they were enveloped — extending backwards to the extreme end of the body. 

 It is in the stage earlier than this, before the tip of the sheath has burst, that the 

 rudimentary pre-pennse are found. 



Summary. 



As stated in the earlier part of this paper, this is the first attempt at anj'thing 

 like an extended or detailed account of the Pterylography of the Megapodes, and even 

 this leaves much still to be done. 



The only other record of the pterylological characters of this group is that of 

 Nitzsch (6). He was perforce obliged to content himself with an examination of a 

 stuffed specimen. In spite of the difficulty of such an unsatisfactory method of 

 investigation, he managed to make out enough to show him " it possesses the general 

 characters of the Gallinacea;," and that the oil-gland was tufted. 



Since then the additions to our knowledge of this subject have been few, and 

 chiefly concern the fact that the young chick is enabled to fly almost immediately 

 after leaving the egg. 



The most important of these is that of Dr Gadow (2), who ^vrites : " Die Jungen, 

 wenigstens einiger Arten, schliipfen vollstiindig befiedert und flugfahig aus ; das Xestkleid 

 ist also embryonal unterdrllckt worden." 



Dr Sclater (13) was apparently the first to point out, on the authority of Mr 

 Beddard, that the wing of at least one species of Megapode (M. rubrifrons = ereniita) 

 was " aquintocubital " = diastataxial. 



The more or less precise details of the pterylological characters of the adult and 

 embryo given in the present contribution will it is hoped be shortly supplemented 

 by similar descriptions of other genera. The facts embodied in this part of the paper 

 are really all new. Again, no one appears to have previously noticed the facts concern- 

 ing the ai-rested development of the outermost primaries, and of the 1st (2nd) cubital 

 remex in the nestling, or the differences in the rate of growth of the manus and 

 fore-arm. All these points, it is interesting to notice, the young Megapode shares 

 with the young Gallus and Opisthocomus. 



The history of the pre-penna3 still needs further investigation. That the nestling 

 was not clothed in a covering of true nestling down has been more or less accepted 

 as a fact for a long while, but the difference between this nestling plumage and 

 definitive feathers seems not to have been previously remarked. 



One or two problems concerning the development of feathers generally have been 

 raised during the present investigation. These however do not concern the questions 

 of pterylosis at all, and will be dealt with in due couree. 



