72 [June, 1846. 



Remarks upon the Anatomy of the Abdominal Viscera of the Sloth, Bradypus 



tridactylus, Linn. 



By Joseph Leidt, M. D. 



A living specimen of the three-toed sloth, which was lately brought to this 

 city from South America, having died a short time since, I have been enabled, 

 through the kindness of Mr. Wood, preparer of specimens in natural history, 

 to procure the greater part of the abdominal viscera and the uterus. 



Descriptions of the anatomy of this animal have been given by several authors, 

 but unfortunately not without a great deal of discrepancy in the statement of 

 the simplest matters of fact, which I cannot account for in any other way than 

 by suspecting several species to have been indiscriminately described as the 

 same. Such cases of discrepancy are by no means unfrequent in Zootomy, 

 arising, no doubt, in many cases, from the too exclusive attention in tbe 

 preparation and preservation of the exterior, to the careless examination, or 

 even total neglect of the interior. 



Regretting exceedingly that I have not been able to extend my observations 

 to the whole anatomy of the animal, I must be content to give a few cursory 

 remarks upon the material obtained, which I proceed to do at once. 



The stomach, according to Cuvier, in his Regne Animal, Tome I. p. 217, 

 "is divided into four sacks analogous enough to the four stomachs of the 

 ruminantia, but without folds or other salient parts in the interior/' Dr. 

 Harlan,* in his account of the anatomy of this animal, writes, "the stomach 

 consists of a large paunch, in no way furnished with compartments like that 

 of the ruminantia, as is asserted by Buffon, who also errs in attributing 

 ruminating faculties to the animal ; but this organ presents a structure differing 

 from that of any other animal with which we are familiar, being furnished 

 with numerous, long, conical cul-de-sacs." 



The specimen of the stomach which I have investigated agrees with the 

 account, so far as it goes, of Cuvier. Taken as a whole, this organ is irregular 

 in shape, large, capacious, and sacculated. It is evidently divided into four 

 compartments, or distinct portions, by contractions, partitions, and difference 

 of structure. The first compartment is the largest and corresponds to the paunch 

 of the ruminantia ; it is separated from the second compartment by a well marked 

 and prominent ridge, is lined by a soft mucous membrane, having in it nu- 

 merous follicles of a large size, is, comparatively with the other portions, thin in 

 its parietes, and has projecting upwards from it, possessing the same structure, 

 a " long, conical cul-de-sac, " the only one found in connection with the stomach 

 in this specimen. The second and third compartments are next in size, and 

 are separated from each other by a partition of the same structure projecting 

 from each side of the cavity of the organ. The oesophagus opens into the 

 second compartment, but as it was cut off close to the stomach I am unable to 

 say anything about it. The lining mucous membrane of these two latter com- 

 partments presents a rigid, rough and thick epithelia, surface resembling in 



Observations on the Anatomy of the Sloth, Bradypus tridactylus* Linn. Medical 

 and Physical Researches, p. 544. Philadelphia, 1836, 



