Jeffries.] 238 [February 7. 



papillae. The belief that they are papillae must have arisen 

 from the examination of sections only, or by mistaking feathers 

 on the tarsus for scuta. 



When we come to consider feathers themselves and ask what 

 was their primitive form, we are left in a maize of uncertainty. 

 It is clear that the remiges and rectrices are not of the first or 

 type form. They stand at one extreme and down-feather3 at the 

 other, being connected by the contour feathers. Palaeontology 

 throws no light; the Archaeopteryx had both rectrices and contour 

 feathers. It is of note, however, that the down feathers are those 

 of the young bird, are the simplest in structure and well adapted 

 for warmth. They are connected with the contour feathers by 

 the half down feathers of the various strathious birds, a group now 

 generally regarded as the most primitive extant. Again, the 

 bases of nearly all feathers are downy, that is the part protected 

 from various modifying causes. 



I am well aware that at the present time, when the tendency 

 is to ascribe everything to one common origin, the above conclu- 

 sions 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 relationship. The laws of growth, though flexible, are 

 invariable, and imprint resemblances on all their products, espe- 

 cially during development. Again, in the epiderm at least, 

 physical relations are much the same, and must imprint their 

 stamp on organisms. 



To meet one argument I call attention to the fact that the 

 Amphibians, from which the higher groups have probably been 

 derived, have no special epidermal appendages except perhaps 

 claws. The scales of the Coecilians are simply flaps, neither fish 

 nor reptile-like scales. Hence it is a mere assumption to suppose 

 that Dinosaurs had scales and still another that the scales of 

 birds and reptiles came from them. Indeed the nakedness of 

 Amphibians is a strong argument against the identity of any of 

 the avian dermal appendages with those of Reptiles or Mammals. 



BIBLIOGRAPHY. 



1. Frommann, C. Ueber die Structure der Epidermis und des Rete 

 Malpighi an den Zehen von Huknchen. Jenaische Zeitschr. f. Nat. 

 1881, 14 Bd. Suppl. Heft, ss. 56-58. 



