In a paper “On a Pneumatic Type of Vertebra from the Lower Karroo Rocks of Cape Colony” (Ann. & Mag. Nat. Hist., ser. VII, vol. xiv, November, 1904, pp. 336–344), by Professor H. G. Seeley, F.E.S., the author makes (on p. 341) some interesting remarks on pneumatic foramina in fossil bones which appear sufficiently important to reproduce here:—

“Doubt has of late been current concerning the significance of pneumatic foramina in fossil bones, and is put forward verbally and in print by Professor H. F. Osborn. In an article in the Century Magazine for September, 1904, similar in scope to the lecture given at Cambridge in August to the British Association, he enunciates the same views. Writing of Ornitholestes, Professor Osborn remarks:— ‘Externally its bones are simple and solid-looking, but, as a matter of fact, they are mere shells, the walls being hardly thicker than paper, the entire interior of the bone having been removed by the action of the same marvellous law of adaptation which sculptured the vertebræ of its huge contemporaries. There is no evidence, however, that these hollow bones were filled with air from the lungs, as is the case of the bones of birds.’