DIEECT TRANSFERENCE FROM THE INTESTINE TO THE STOMACH. 547 



Cysticercus cellulosce and Tcenia solium were as yet unapprehended, 

 and when the presence of tape-worm in cases of bladder-worm might 

 attract no special attention. 



It is, however, by no means necessary that the transmission of a 

 brood should take place through the mouth. The eggs are, indeed, in 

 all cases subject to the action of the gastric juice (p. 153), but a trans- 

 ference from the intestine into the stomach may take place directly 

 when the contents of the former are driven forwards by antiperistaltic 

 contraction. Sometimes it is but single proglottides which pass back 

 in this way, sometimes longer stretches of joints, so that an infection 

 may thus be brought about, resulting in an abundant occurrence of 

 Cysticerci. Such being the case, it is quite possible that one or other 

 of the above-mentioned cases was due to a self-infection of this sort. 



The fact that there are numerous cases of tape-worms (Taenia 

 solium of course) where the host never becomes infected by bladder- 

 worms, cannot, of course, be used as an argument against the 

 assumption of this " eutocoelic " self-infection. It could be used as 

 such only if the digestion of the egg membranes and the liberation of 

 the embryos were possible while the eggs were still in the intestine. 

 This is, indeed, alleged by Klichenmeister,^ and more recently by 

 Klebs ^ and Lewin. In this case, the existence of a tape-worm host 

 without bladder-worms would be exceptional, while we know that 

 exactly the reverse is true. 



In rare cases the transference of proglottides into the stomach 

 may be facilitated by the abnormal position of the tape- worm. Some- 

 times one finds the worm hanging upwards ^ in the intestine, so that 

 the proglottides are approximated to the stomach. It is doubtful, 

 however, whether this position was permanent. At any rate, one mxist 

 remember that the position of the tape-worm in the intestine is de- 

 termined by extraneous forces (pressure of the chyme, contraction of 

 the intestine, &c.), as well as by the motions of the worm itself. 



The proglottides passing into the stomach from the intestine 

 can cause infection only when they remain some considerable time 

 in the former. When they merely pass into the stomach to be 



' " Parasiten," first edition, p. 12. Kuohenmeister maintains that the embryos may be 

 liberated, and may develop even in the cesophagus. Only after I published ray objections 

 ("Blasenbandwiirmer," p. 102), and proved experimentally that the embryos could only be 

 liberated by the action of the gastric juice ("Parasiten," first edition, p. 116), did he change 

 his opinion. That did not, however, hinder him from asserting in pp. 98 and 115 of the 

 new edition that he was the first to show that a transference into the stomach was neces- 

 sary for the liberation of the embryos. We do not need now-a-days seriously to contra- 

 dior, or disprove the statement of Kuohenmeister, that the bla'lder-worms found in the 

 peripheral regions, such as the conjunctiva, arise from direct immigration from outside. 



» "Handbuch d. pathol. Anat.," p. 301, 1868. 



» A case of this sort (by ^^fj^^J'^^^J^^^o^'^^^'"^' "*' "^ ^^" 



