232 THE VOYAGE OF H.M.S. CHALLENGER. 



either useless or even detrimental to the animal, and had hence undergone a process of 

 atrophy, and become converted into non-contractile tendinous bands. 



It appears to me, therefore, that, relying on the anatomy of the Penguins, we must 

 conclude that they form the surviving members of a group which had early diverged from 

 the primitive avian stem,* but that at the time when the separation took place the mem- 

 bers of that stem had so far diverged from the primitive ornithoscelidan form as to be 

 possessed of anterior extremities, which instead of forming organs of terrestrial, had 

 become transformed into organs adapted to aerial progression, in other words, into true 

 wings. 



If this view be correct, palseontological research ought in the course of time to disclose 

 the existence of numerous Spheuiscidine remains, which maj^ enable us to trace the line of 

 descent of the Penguins of the present day from the original avian stem, and through it 

 the relationship which exists between the modern Sjihemscits or Emhjptes, with theii- 

 separate metatarsal bones and aborted wings on the one hand, and the majority of modern 

 birds, with their conjoined metatarsal bones and perfect wings on the other. 



In view of these observations it seems hopeless to attempt at present to trace the 

 affinities of the Penaaiins to other genera of existins; birds ; and although in many 

 respects they appear more nearly to resemble the group of palmipede birds than any 

 other, yet I think it unnecessary, considering the present state of our knowledge of the 

 anatomy of the latter, to found hypothetical conclusions as to the exact affinities of 

 the Penguins upon anatomical data which eveiyone must acknowledge to be altogether 

 insufficient for the purpose. I shall therefore content myself with remarking, in the 

 words of Gervais and Alix, that " Si, an lieu de se borner a constater Ics affinites, on 

 veut se placer au point de vue de la recherche d'un tj^e ancestral commun aux Sphenis- 

 cides et aux Palmipedes, on voit que ce tj'pe hypothetique ne saurait etre arrive a 

 produire celui des Spheniscides qu'aprfes de nombreuses modifications."'^ 



' In corroboration of this opinion I suljjoin the following : — 



" When describing the fossil bones of the large Penguin, Palceeudyptes antarcticus, Huxley, in a paper publisheil in 

 last year's volume of our Transactions, I find that I overlooked two very fine specimens that were in the museum. 



" They were presented by Mr. Charles Traill, who found them in the white calcareous sandstone which is excavated 

 at Fortification Hill, near Oamam, in Otago, and which is well known as the Oamaru limestone. 



"The bones are beautifully preser\'ed in this matrix, which has been carefully cleared away to allow of the 

 examination. 



" They are the left humerus and coracoid of the right side, and belonged, I liave no doubt, to the same individual 

 bird as the metacarpal figured in last year's volume (pi. xvii. fig. 3). The humerus is one-sixth of an inch larger than 

 the same bone in the Brighton fossil, and has a more marine appearance. Judging from the proportion of the bones, 

 they must have belonged to a bird that had a stature of from 6 to 7 feet. 



" Captain Hutton said he considered the age of the strata containing these bones to be upper Eocene, and that they 

 are therefore among the oldest bird remains known." — Hector, J., Trans. New Zealand Inst., vol. v. p. 438, 1872. 



- Osteologie des Manchots, p. 44. 



