Zoological Society. 525 



as will be shown by the following measurements, which are given in 

 vulgar fractions of an English inch ; the average size of those of the 

 Ibex from Candia {Capra Caucasku, Guld.), = 1-7020 inch, and of 

 the pale globules of the blood, = 1-3200 inch ; of the Common Goat 

 {Capra Hirci/s, Linn.), = 1-G3G6 inch, and of the pale globules of the 

 blood, = 1-3032 inch ; and of the Napu Ivlusk Deer (Moschus Java- 

 ulcus, Pallas), = l-1232o inch, and of the pale globules of the blood, 

 = 1-3200 inch. 



I may add that Mr. Siddall, who has lately at my request mea- 

 sured the blood-corpuscles of the Ibex and of the Goat, has obtained 

 almost exactly the same results as those above specified. 



Mr. Gulliver also communicated a paper " On the Blood-Corpus- 

 cles of the British Ophidian Rej)tiles." To this communication are 

 added some observations on the figure of the blood-corpuscles of other 

 oviparous "\''ertebrata. 



"The observations were made on perfectly fresh blood, and the 

 corpuscles measured as they floated in the serum. 



•' Tliough the blood-discs of Birds and Reptiles preserve their 

 shape very clearly wdien rapidly dried on a slip of glass, they generally 

 appear in this state slightly but distinctly smaller than when sus- 

 pended in the serum of recent blood; whereas, when the blood-discs 

 of Mammalia are dried in precisely the same way they are commonly 

 slightly larger than in the wet state, as I have noticed more particu- 

 larly in the ' Philosophical Magazine' for January and February 1840, 

 pp. 25 and 105." 



" In Mammalia the envelope of the corpuscle is more delicate, more 

 susceptible of contraction and of modifications of form, and apparent- 

 ly softer, than in Birds and Reptiles ; so that the corpuscles of Mam- 

 mals are more liable to shrink a little soon after removal from the 

 circulating channels, than the corpuscles of Birds and Reptiles ; and 

 it may be that this softness of the blood-disc of Mammals allows it 

 to spread out in some degree, even when dried ever so quickly. But 

 it is more probable that the corpuscles preserve their usual size and 

 form when dried almost instantaneously, and that the shrinking or 

 modifications of shape which the corpuscles may undergo in liquid, 

 coagulating, or slowly-dried blood, may be influenced as much by 

 changes in the surrounding fibrine as by a contractility inherent in 

 the corpuscles. The envelope of the blood-disc of Fishes is much 

 more delicate and evanescent than the same part in Birds and Rep- 

 tiles ; hence in the blood of Fishes, even soon after death, the nuclei 

 will be observed in great abundance, while the envelopes have par- 

 tially or entirely disappeared ; and the form of the entire corpuscles 

 is not so easily preserved by drying as in the other oviparous verte- 

 brate animals." 



The following average dimensions of the blood- corpuscles of the 

 Slow Worm, Snake, and Viper, deduced from measurements of the 

 small, large, and common-sized discs, are aU exjiressed in vulgar 

 fractions of an English inch. L.D. stands for Long Diameter, and 

 S.D. for Short Diameter. 



March 19, 1842. — Slow Worm {Anguis frarjUis, Linn.) : L.D. = 



