95 



June 11, 1844. 



George GuUiver, Esą., in the Chair, 



Letters \vere read from William Willshire, Esq., Corr. Mem., ac- 

 companying a specimen of the Aoudad, Ovis Tragelaphus, from Moga- 

 dore, which he presented to the Society ; and from the Rev, R. T. 

 Lowe, Corr. Mem., presenting specimens of Fish from Jamaica. 



Also a communication from H. Bourchier,Esq., Corr. Mem., Malta, 

 relating to two Ostriches presented to the Society by Colonel War- 

 rington. 



" On the Blood-corpuscles of the Two-toed Sloth, Bradypus didaC' 

 tylus, Linn.," by George Gulliver, F.R.S. 



From an observation which I have lately made, it results that the 

 Two-toed Sloth is one of the very few animals that has blood-discs 

 considerably larger than those of Man. 



The following measurements of the blood-discs of the Sloth are 

 given in vulgar fractions of an English inch : — 

 1-3200^ 



Common sizes. 



1-3000 

 1-2888 

 1-2823 

 1-2769 

 1-2664 

 l-2583_ 



1-2286 1^''*^^"^'' 



1-2865 Average. 



M. Mandl* discovered that the blood-corpuscles of the Elephant 

 are the largest at present known belonging to the Mammalia, and I 

 subseąuently found that those of the Capybara -vvere, as far as we 

 then knew, next in size, as noticed in my Appendix to Gerber's 

 Anatomy, pages 5, 8, and 50. 



But it now appears that the blood-corpuscles of the Sloth are 

 larger than those of the Capybara, and, among mammiferous animals, 

 second only in magnitude to the corpuseles of the Elephant. 



For the sake of comparison, some of my measurements of the 

 average size of the largest blood-discs of Mammalia are here set 

 down in the order of the magnitude of the discs, and in vulgar frac- 

 tions of an English inch. 



* Anatomie Microscopiąue, Paris 1838, Prem. Liv. p. 17. M. Mandl's 

 observation refers to the blood-corpuscles of the African elephant ; it was 

 those of the Asiatic species that I examined. 



No. CXXXVI. — Proceedings of the Zoological Society. 



