NATURAL HISTORY SOCIETY OF GLASGOW. 273 



think that they were anything more than common English Puffins, 

 which, from having been hatched late, or perhaps from disease, 

 had not attained their growth when the next breeding season 

 came round. 



I wish to make some remarks on the Puffin's osteology. I have 

 before me ten Puffins' breastbones, nine of which were from 

 birds killed near these islands. I find they differ from the 

 breastbones of Guillemots and Razorbills, in having two pos- 

 terior emarginatious, — one being an indentation, the other a 

 hole. In this, as in many other respects, they resemble the breast- 

 bone of the Black Guillemot, which sometimes, but not always, 

 has two emarginations. It is generally believed that the holes 

 ossify with age, and that in a very old bird they are closed up. 

 There is, however, much variation, as I have skinned a Puffin 

 in which one emargination (the hole), on the left side, was 

 completely changed to bone, and on the other side it was nearly 

 so. Much may be learned as to the affinity of birds to one 

 another by an examination of *their osteology. 



Guillemot, Alca troile, L. 



The Guillemots live on some rocks called the Pinnacles, and I 

 have seen such a stream of them go swarming off those aforesaid 

 rocks, that I can only liken it to a busy ant-hill, or bees on a 

 sunny day in summer time. I really think that, for their size, 

 there are more Guillemots on the Pinnacles than on any similar 

 rock anywhere, and I do not forget the multitudes at Flamborough 

 and Ailsa Craig, and other places which I have only read of If 

 the whole Guillemot population were numbered, the Fern islands 

 would fall very far below most places ; but compare the Pinnacles 

 with a similar area anywhere else, and I think they will stand 

 first. They are not very high, and the eggs are easily taken. 

 The egg-gatherer, who lives on one of the islands, employs a 

 ladder for the purpose. Either he or one of the boatmen informed 

 me that blood was sometimes seen upon the rocks, which I 

 thought showed that, as in human beings, so in birds, when the 

 density of the population exceeds the area, fights ensue. 



Razorbill, Alca torda, L. 



I have twice obtained the Razorbill at the islands, but it is far 

 from common. On my last visit I did not see one. 



