-226 THE VOYAGE OF H.M.S. CHALLENGER. 



arrangement of the feathers surrounding the head, but Eudyptes clirysoloplius is altogether 

 a larger and heavier bird than Exidijptes clirysocome. Moreover, an examination of the 

 skeleton of Eudyptes chrysolophus shows that its vertebral column as a whole is not only 

 about 2 inches longer than that of Eudyptes clirysocome, but that every bone both of the 

 trunk and limbs is larger and stouter than the corresponding bones of Eudyptes clirysocome. 

 A. consideration of tliese points by themselves would at once have led me to agree with the 

 authors mentioned, and to have concluded that Eudyptes chrysolophus was specifically 

 distinct from Eudyptes chrysocome. 



On the other hand, a comparison of the internal anatomy of the two birds shows that 

 in evSry essential point that of Eudyptes chrysolophus agrees with that of Eudyptes 

 chrysocome, and we look in vain for any anatomical feature in respect of the osseous, 

 digestive, or respiratory organs which will enable us to decide definitely that any portion of 

 these organs belongs to the one rather than to the other of these so-called sjiecies. The 

 stomach in both presents a proventricular gland of the same form; in both the small intestine 

 varies in length from twelve to thirteen times the length of the vertebral column ; 

 in both the length of the septum tracheae relatively to that of the trachea itself is the 

 same ; and in both the structure and relations of the syrinx are similar. The bones 

 of Eudyptes chrysolophus, as I have said, are larger than those of Eudyptes chrysocome, 

 and the bulk of the whole bird exceeds that of Eudyptes chrysocome by one-eighth, and if 

 we place the skulls of Eudyptes chrysolophus alongside of that of Eudyptes chrysocome, 

 the large size of the skull of the former is strikingly apparent. At the same time, I 

 failed to distinguish any specific character in the skull, apart from mere size, Avhicli would 

 serve to distinguish the one from the other. Lastly, I have observed, when comparing 

 the skulls of the three varieties of Eudyptes chrysocome with that of Eudyptes chrysolophus, 

 that in respect of size there is a remarkable gradation from the smallest skull of 

 Eudyptes chrysocome, through the larger skulls of the same species, to that of Eudyptes 

 chrysolophus. The skull of Eudyptes chrysocome from Kerguelen is the smallest, and is 

 exceeded slightly in size by that of Eudyptes chrysocome from Tristan, while the skull of 

 Eudyptes chrysocome from the Falklands is the larger of the three. When the skull of 

 Eudyptes chrysolophus is placed alongside that of the latter, although the disproportion in 

 size is rather greater than that which obtains between the skulls of any of the three 

 varieties of Eudyptes chrysocome, yet the skull oi Eudyptes chrysolophus ^resQuts no more 

 specific distinctive feature which would serve to distinguish it from the largest skull of 

 Eudyptes chrysocome. than is possessed by the largest skull of Eudyptes chrysocome, as com- 

 pared with the smallest skull of the same species. 



To sum up. I believe that if difference in size and colour of a few feathers of the 

 head, combined with larger size of one of the birds as a whole, justifies us in asserting 

 specific distinction between two birds, then, undoubtedly, Eudyptes chrysolophus is 

 specifically distinct from Eudyptes chrysocome. On the other hand, the striking similarity 



