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Show 1870.] MR. GULLIVER ON THE BLOOD-CORPUeCLES. 97 experiments relating to these points, save the few valuable but fragmentary ones of that eminent physiologist the late John Davy. In short, the relation of animal heat to the size and proportion of the red corpuscles of the blood still requires an ample and careful set of experiments. From all that is at present known it appears that, cceteris paribus, the smaller these corpuscles the greater will be the heat of the animal, since a minute subdivision of a given bulk of them will afford a corresponding increase of their aggregate surface for the transit of oxygen. The comparative smallness of the blood-disks of the diminutive species of a family of Mammals and of the class of Birds may be a provision against the greater proportionate loss of heat in the little members of such family or class. Dr. Davy has shown that warm-blooded fishes have a large proportion of blood and red corpuscles, while that proportion is remarkably less in fishes that are but little warmer than the water in which they live. And to this excellent observer we are indebted for precise experiments on the increase of the heat in M a n when the circulation of the blood is hastened through the lungs and body. The warmth of the Python during incubation at the Society's Gardens, as shown by the important observations of Dr. Sclater (Proc. Zool. Soc. 1862, p. 365), was probably due to accelerated circulation of the blood, and increased chemical action connected therewith, as in a fever. In one of his interesting experiments, Dr. Sclater found the temperature of the female Python as high as 96°, and of her male mate 76°, while the air of their den was only 60°. Such facts, with Dr. Davy's discovery of the regular warmth of certain Fishes, as much invalidate Prof. Owen's distinction of " Hsematocrya" and " Haematotherma," as, according to his statement, the air-cavity of the humerus of the Pterodactyle "breaks down" Cuvier's distinction of Birds from Lizards by the air-passages in the bones. Historical Notices.-The records of discovery concerning the constituents and properties of the blood make but a sorry chapter in its written history, and one, indeed, that had better remained unwritten than overwhelmed, as it was, with confusion and injustice. In the Introduction and Notes to Hewson's works, it was part of my duty to correct Prof. Owen's contributions to such mistakes; and I now regret that the common truth of a branch of physiological history and my own just claims still require vindication from his pretensions and the indiscreet zeal of his friends. The early tables of measurements by Prevost, Dumas, or others, exemplified the smallness of the blood-disks of Ruminants in those of the Sheep, Goat, or other members of the order. And the red blood-corpuscles of the Goat were the smallest known before my discovery, read at the Med. Chir. Soc. Nov. 26, 1839, of their singular minuteness in Tragulus ; while m y measurements thereof, and of the blood-disks of the Camels and several other Ruminants, and of the Marsupials, were, as then noted by the Editor, communicated to the 'Philosophical Magazine' just three days previously. Yet these plain truths are always suppressed by Prof. Owen in order to support his own pretensions to the discovery and his amusing PROC. ZOOL. Soc-1870, No. VII. |