VII. 



NOTES ON THE BLOOD-CORPUSCLES OF THE 

 TWO-TOED SLOTH, CHOLOPUS DIDACTYLUS, 

 AND OF THE ELEPHANT, ELEPHAS INDICVS. 



Mr. H. N. Moseley \ of Exeter College, called my attention a 

 few days ago to the appearance of nucleation which a slide of the 

 dried blood-corpuscles of the Two-toed Sloth, Cholopus didactylus, 

 presented under a quarter-of-an-inch object-glass of Powell and 

 Lealand's. I had a short time before met with a statement in the 

 recently-published second part of Dr. Kiihne 's 'Lehrbuch der 

 Physiologischen Chemie,' p. 195 2 , to the effect that only some 

 mammals, the sloth and the camel, possessed nucleated blood-cor- 

 puscles. And this coincidence determined me to use such means as 

 we had at our disposal for settling a point as to which all recent 

 authorities were, as far as my knowledge went, opposed to Dr. 

 Kiihne. 



The employment of a twelfth-of-an-inch object-glass, by the 

 same makers, has convinced Mr. Moseley and myself that, though a 

 certain number of the dried blood-corpuscles of the sloth do contain 

 one or more nuclei more or less roughly hewn, and irregularly and 

 eccentrically placed, still the immense majority of them possess the 

 non-nucleated character ordinarily assigned to the mammalian red 

 blood-cell. The larger size of the blood-cells of the two-toed sloth, 

 the largest next to those of the elephant put on record amongst 

 mammalian blood-cells by Mr. Gulliver 3 , may in more ways than 

 one have rendered an examination of them by a low power amenable 

 to fallacy, and recourse to those of a higher power necessary. In 



1 Now Professor Moseley, Dr. Rolleston's successor in the Linacre Chair. 



a ' Lehrbuch der Physiologischen Chemie,' von Dr. W. Kiihne, p. 195 : — 'G-ewiss ist 

 es htichst auffallend dass nur das Blut der Saugethiere sich durch den Mangel dieses 

 Bestandtheils (des Kerns) auszeichnet, dass nur einzelne (Kameel, Faulthier) unter 

 ihnen kernhaltige Blutkorperchen besitzen.' 



3 Hewson's Works, p. 238. 



