Intestinal Invagination. — Intussusception in Solipeds. 345 



records a case in which 24 feet were invaginated, and Rej' a case 

 of quadruple invagination at the same point. 



The invagination of the caecum into the colon is frequent, the 

 blind end of the caecum falling into the body of the same organ, 

 and this continuing to increase until it passes on into the colon, 

 and even carries a portion of the small intestine with it. This 

 lesion is more rare in solipeds because the caecum has its blind end 

 lowest and gravitation opposes its invagination. 



Resulting Lesions. In any case of invagination it must be 

 noted that it is not the intestine alone which slips into its fellow, 

 but it carries with it its attaching mesentery, which, dragging on 

 one side of the invaginated gut, shortens and puckers that and 

 turns its opening against the wall of the enclosing gut so as to 

 block it, while the opposite or free side passes on and tends to 

 form convolutions. If the outer and enveloping intestine is too 

 small to allow of this, the detaining mesentery of the invaginated 

 mass must be torn or stretched unduly and its circulation and 

 innervation correspondingly impaired. When the invagination 

 occurs of one portion of the small intestine into another of nearly 

 equal size, the resulting mass is firm like a stuffed sausage, and 

 this enlargement and consolidation ends abruptly at the point of 

 visible entrance of the smaller contracted portion, into the larger 

 dilated one. 



If recent, the invaginated mass is still easily disengaged from 

 the enveloping portion, though considerably congested and dark 

 in color in proportion to the duration of the lesion. When it has 

 been longer confined the incarcerated portion is the seat of 

 extreme congestion, and extravasation, and has a dark red or 

 black color. The exudation into its substance, which is especially 

 abundant in the mucosa and submucosa, produces a thickening 

 which may virtually close the lumen, and on the opposing peri- 

 toneal surfaces leads to adhesions which prevent the extraction of 

 the imprisoned mass. The interruption of the circulation and the 

 compression of the invaginated mass, leads soon to necrosis and thus 

 a specially offensive odor is produced, and if the animal survives 

 the whole may be sloughed off and passed with the faeces, the 

 ends of the intussuscepted portion and of that receiving it mean- 

 while uniting and becoming continous with each other. 



Symptoms. These are the violent colic of ob.struction of the 



