Miscellaneous. 133 



interna is prolonged upon the capillaries in the form of a sheath, 

 which is wide and funnel-like at first, but soon embraces the ves- 

 sels so closely as to become indistinguishable from their proper 

 wall ; so that, notwithstanding the existence of a sheath, there is no 

 perivascular space about the retinal capillaries, such as His has de- 

 scribed in the brain or spinal cord, and has stated to occur in the 

 retina and elsewhere. 



In all other mammals, except the hedgehog, as far as my present 

 knowledge extends, the arteries, veins, and capillaries lie in the re- 

 tina. In fish, amphibia, reptiles, and birds, however, as H. Miiller 

 and others (myself as regards amphibia and reptiles) have shown, 

 the retina is absolutely nonvascular, the absence of proper retinal 

 blood-vessels being compensated for in fish, amphibia, and some 

 reptiles by the vascular net which in these animals channels the 

 hyaloidea, and by the highly vascular pecten present in other reptiles 

 and in birds. Thus it is possible to divide vertebrates into two classes, 

 according as their retina is vascular or non-vascular ; and these 

 classes would be connected by the hedgehog, the larger branches of 

 whose vasa centralia, lying upon the membrana limitans in intimate 

 relation with the hyaloidea, represent the equivalent vessels of the 

 hyaloid system, which forms so exquisite a microscopic object in the 

 frog ; whilst the capillary vessels channelling the retinal tissues 

 occupy the same position which they do in most mammalia. 



MISCELLANEOUS. 



On the Origin of the Name ^^ Penguin" 



To the Editors of the Annals and Magazine of Natural History. 



Gentlemeij, — More than ten years ago it occurred to me that the 

 name " Penguin" or " Pengwin," applied to certain sea-fowl which 

 are unable to fly, was a corruption of " pen-wing " or " pin-wing," 

 meaning a bird that had apparently midergone the operation of 

 pinioning or " pin-winging," as it is, in at least one part of England, 

 commonly called. Lately Mr. Henry Reeks, who has been success- 

 fully pursuing the investigation of natural history in Newfoundland, 

 has kindly informed me that in that country the name " Penguin " 

 used there to signify the Alca impennis of Linnaeus, is invariably 

 pronounced " Pen-wing ;" and this fact seems to confirm the suppo- 

 sition I had formerly entertained. I shall be greatly obliged to you 

 by allowing me to mention in your pages this suggestion, which, so 

 far as I am aware, has not been before published, especially as 

 neither of the only two derivations of the name which I have seen 

 assigned — the first from the Latin pm^w6c?o (fatness), the second from 

 the Welsh pen gwyn (white head) — appears to me at all probable. 



I am, Gentlemen, 



Your obedient Servant, 

 Bloxworthj July 22, 1869. Alfred Newton. 



