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strain being placed upon a single muscle or ligament. The very strong clavicles, and the thick 

 coating of feathers which lie between the wings and the body, must both play an important part 

 in easing off the effect of the blow caused by the bird striking the water. The clavicles being 

 fused to the end of the ridge of the sternum, would act as a spring, much in the same way as 

 the top joint of a salmon-rod ; whilst the feathers would act as padding, and help to prevent 

 any jar. 



" I send you with this the breastbone of a Gannet, which will make the above description 

 more intelligible. It is the identical breastbone which I had in December 1876. I presented 

 it to the University Museum at Oxford ; and Professor Rolleston has very kindly lent it to me for 

 your use. If you decide to have it figured, I would suggest that you should have two drawings 

 of it — one of the front, showing the direction of the articulation of the coracoids to the sternum, 

 and one of the back, which will show better the shape and remarkable development of the 

 wedge. The significance of the above peculiarities in the Gannet comes out more clearly if the 

 sternum of the Gannet is compared with that of the birds most nearly allied to it, say with the 

 Cormorant. 



" The side view of the Gannet's sternum seems to me not less remarkable than the front 

 and back. All the parts are enormously strong; and each clavicle, with its coracoid and the 



