DIRECTIONS FOB OBTAINING MATERIAL 95 



board and split lengthwise with scissors with protected points. This 

 manipulation should be performed with great care, in order that any 

 Helminthes present in the bowel may not be damaged. The blunt 

 end of the scissors should be inserted into the lumen of the bowel, and 

 it should be kept quite close to the bowel-wall, of which only a small 

 portion should be cut at a time. When split along its entire length, 

 the bowel is opened out, fixed with pins to the board, and its contents 

 examined. Helminthes of sufficient size to be perceived with the 

 naked eye will have been seen during the process of .cutting, and their 

 site of attachment should now be noted. Many species favour special 

 sections of the small intestine, just as others are only to be found in 

 the stomach or the caecum Regular distribution of the same species 

 through the entire length of the small bowel is very rare in a freshly 

 killed host. 



Position, method of attachment, and movements of the Helminthes 

 should be noted and the free individuals should be lifted out with the 

 spatula and put into shallow vessels containing normal saline solution. 

 The Helminthes which are not free should next be detached, wherever 

 possible, from the bowel-wall. This can generally be accomplished 

 by digging into the mucosa at the point of attachment, and bringing 

 a portion away on the spatula with the worm. The method is not 

 always successful, however. Many Cestodes (though this does not 

 apply to those of the cat) as well as Echinorhynchus varieties, strike 

 so deeply into the mucosa that they penetrate the muscular structure 

 of the bowel-wall. Liberation, in these cases, is much more difficult 

 and is frequently to be effected only by special preparation under the 

 microscope. It is not advisable, in any case, to release all the attached 

 individuals. In certain cases, the portion of the bowel-wall which has 

 become changed by the agency of the parasite should be cut away 

 together with the scolex, and the two fixed whole together. This 

 should be carried out as expeditiously as possible, as the worms 

 frequently release their hold when disturbed or as the bowel cools, and 

 it is rare to find them attached except in a quite fresh organ. 



The Helminthes most frequently encountered in the intestine of the 

 cat are Ascaris canis (= A. mystax) and Dipilidium caninum (=Tcenia 

 elliptica =T. cucumerina). Both varieties, and especially the latter, are 

 as a rule found in large numbers. 1 Both may occur in man and, for this 

 reason, they have a special practical interest. Ascarides (fig. 28) live 

 free in the lumen of the bowel ; D. caninum, the " cucumber-worm," 



J In Italy, D. trinchesii*Di&m., and D. pasqualei, Diam., are found in the domestic 

 cat, while D. chyzeri, v. Eatz, is found in cats in Hungary. (See V. Diamare, " II 

 genere Dipylidium," Naples, 1893; also v.Katz, Centralbl.'f. Bakt., Par. und Inf., 1, 

 part xxi, 1897, p. 465). 



