THE PUFFIN 51 



grasp upon fish is, therefore, very improbable. That they have been 

 developed for some other reason, and yet assist, in the case of the 

 puffin and razorbill, to maintain the fish in place, is an arguable 

 position ; but even then it has yet to be proved that the spines are 

 large and strong enough to prevent a fish becoming detached from the 

 palate and upper mandible when released from the grip of the bill. A 

 more plausible theory is that the fish are held in place by the tongue 

 each time that the bill is opened. This is probably also what happens 

 in the case of birds, like Thrushes or Wagtails, which are able to seize 

 and hold yet another insect or worm without disturbing the bundle 

 already in the bill. As these species are without palatal spines, it 

 would be difficult to suggest any other explanation. And if the 

 explanation suffices for them, why should it not suffice for the puffin 

 and razorbill ? The palatal spines must, however, serve some purpose. 

 What this is may well remain an open question. 



Whether the external shape and the size of the beak is of aid in 

 giving a firmer grip upon the fish is not yet clear, but in this connec- 

 tion it is instructive to note that the beak of the puffin and razorbill 

 are much alike in shape, and differ considerably from that of the 

 guillemot ; also that during the breeding season, that is at the time 

 when most fish have to be caught, the beaks of the first-named 

 species are actually larger in size than in the winter. This remark- 

 able fact was discovered, in respect to the puffin, by a French 

 zoologist, Dr. Bureau. 1 He showed that after the breeding season, 

 in August, the basal half of the beak, the pieces constituting the 

 blue area, and the yellow line bordering the outer edge of the 

 blue (Fig. 1, B}, scale off in plates. I have, in fact, been able to 

 lift easily with a penknife the blue plate on the upper mandible of 

 a freshly killed specimen examined on June 22. Underneath it 

 was a fleshy layer or pad, which presumably hardens to form 



1 Bulletin de la Sod6U Zoologique de France, vol. ii. 377-399. Translated in part in the 

 Zoologist, 1878, 233. The same observer found that similar changes take place in other species 

 of puffin and of related genera, for which see the Bulletin Soc. Zool. France, vii. 270 ; viii. 348. 



