iSS.(.| l^ntnt IJlfialiire. 1 8^ 



been hascii inainl\ on the I'oininon cliirk and cluckliiiy, yet nian_\' t'oi"nis 

 in other orders have been examined, and in all cases found to agree so 

 closely with the two types specially investigated, that '-any statement 

 made for the chick may in all pi-()bal)ilit\- be extended to cover the entire 

 group of carinate birds." 



The scope and character of the paper may be furthci- indicated b\ the 

 following transcript of its sub-headings : — 



(i) Adult Skin; (2) Development of the Epiderm ; (3) Development 

 of Embryo Feathers; (4) Development of Pinfeathers ; (5) Scuta; (6; 

 Development of Scuta ; (7) Claws; (8) Development of Claws ; (9) The 

 Bill; (10) Development of the Bill; (11) Combs and Wattles; (12) 

 Spurs; (13) Toe-pads; (14) Spines of Mouth ; (15) Summary; (i6j 

 Bibliography. The literature of each special subject is first passed in 

 review, then the adult structure of the part is considered, and finally its 

 mode of development. The morphology of the various appendages is 

 treated in the general ■Summary.' 



Many authors have assumed a priori that scuta are morphologically 

 identical with the scales of reptiles. — a proceeding our author claims to 

 be 'totally unscientific,' and pronounces the evidence against this view to 

 be overwhelming. Neither are spurs "to be classed as modified scuta, as 

 has been done by those who consider scuta and scales to be the same 

 thing." 



The modern view of feathers and hairs is that they are allied structures, 

 though Gegenbauer speaks of them as divergent structures. "It is now 

 known, however, that their early stages are the exact reverse of each 

 other." For various reasons our author -'considers feathers and hairs as 

 disti>ict structures." Feathers and scuta are also said to be not homolo- 

 gous ; the former originate as papillee, the latter as folds, and so remain 

 through life. "At no period .... is there the slightest resemblance in 

 form"; while "all the peculiarities of the mucous layer separate the feather 

 from the scale." The "fact that feathers grow upon scuta shows them to 

 be distinct structures." 



In closing the author says: "I am well aware that at the present time, 

 when the tendency is to ascribe everything to one -common origin, the 

 above conclusions will be distasteful to many. Yet, when examples of 

 the separate origin of like structures — analogous organs — are so abundant, 

 it seems rash to consider a slight resemblance a proof of genetic relation- 

 ship." The fact that "Amphibians, from w'hich the higher groups have 

 probably been derived, have no special epidermal appendages except per- 

 haps cl-aws," he considers a "strong argument against the identity of anv 

 of the avian dermal appendages with those of Reptiles or Mammals." — 

 J. A. A. 



Shufeldt on the Osteology of the Mountain Plover.* — This is another of 

 Dr. Shufeldt's osteological monographs, in which a member of the Plover 



* Observations upon the Osteology of Podasocys montaniis. By R. W. Shufeldt, M. 

 t)., Captain Medical Corps U. S. Army [etc. , etc.] . Journ. Anat. and Physiol., Vol, 

 XVni, pp. 86-102, pi. V. 



