648 DR. p. CHALMERS MITCHELL ON THE 



coi-1'ect, my facts would have to be interpreted according to the 

 alternative I have just given. But I am not convinced by 

 Pyci'aft's deduction from his observations on the ontogenetic 

 changes in the wing. The development of the individual is 

 partly a process of latent differences becoming visible, and 

 because a diastataxic bird appears to be eutaxic at a very early 

 stage, it does not follow that eutaxy was primitive. I am mucii 

 more impressed by the general view that passerine birds are 

 plainly the most specialized of all birds, that they are eutaxic, 

 and that the members of diastataxic groups which have become 

 eutaxic are in other respects most passerine-like. In the absence 

 of any convincing theory of the phylogenetic origin of diastataxy, 

 all peculiarities in the arrangement of feathers are interesting 

 and may come to have siguiticance, and so I have digressed 

 with regard to the wing of Bcdamiceps. 



It is plain that the pteiylosis of Balceniceps is of the same 

 general chai'acter as that in Storks, Herons and Sco'jnts. To my 

 eye, the general appearance and coloration suggest affinity with 

 Herons rather than with Storks. The sedate habit of standing 

 silently on aiiy little eminence, the absence of the habit of 

 clattering with the beak, which we noticed in the Gardens, and 

 the reported heron-like bending of tlie neck in flight, confirm 

 this view. But the actual details of the feathering do not 

 confirm it ; without any doubt, so far as pterylosis can be relied 

 upon as indicating affinity, Balceniceps is more Stork-like than 

 Heron -like. 



Petherick, however, (34) has recorded that the young ran about 

 with extended wings making a " rattle-like noise produced by 

 the snapping of their bills." 



Foot and Claro. — The hind toe (hallux) is usually carried 

 pointing backwards, but is freely movable in eveiy direction. It 

 is on the same level as the other toes, as in Herons and Scopus, 

 not slightly elevated as in Storks. There is no trace of a web 

 uniting any of the toes, whereas in Herons and Scopus there is 

 usually a distinct web uniting the third and fourth toes, and in 

 Storks all three front toes are united by web. 



A good deal of confusion, which I am able to dispel, has crept 

 into the liteiatin^e with regard to the condition of the claw of the 

 third digit of the foot. It is well known that the inner edge of 

 this claw is pectinated in Herons and unbroken in Storks. 

 Professor Reinhardt (37, p. 378) stated that Balceniceps had not 

 a comb on the middle claw, adding that this absence afforded " a 

 strong warning not to class it with the Boatbill, as this peculiar 

 serrature never fails in any member of the Heron tribe." Gadow 

 (16, p. 137) divided the Ardete into Family 1. Ardeidte, dividing 

 the latter into the sub-families Ardeinse and Balaenicipitinae, 

 mentioning as a character of the former " Mittelkralle gezjihnt," 

 and of the latter " Mittelkralle nicht gezahnt," and Family 2. 

 Scopida% including in the definition of the latter, " Mittelkralle 

 gezahnt." Beddard (3, p. 289) cites Professor Reinhardt s opinion 



