EFFECTS OF WANDERING EMBRYOS. 135 



It is only in rare cases, according to Lewis, that the Hsernatozoa 

 give rise to more or less serious disturbances in other organs through 

 ruptures or capillary embolism. Gruby and Delafond have observed 

 epileptic fits in dogs infected with these parasites.^ 



When the embryos have finished their wandering, and have settled 

 down and begin to grow, new phenomena appear in place of the 

 former ones, and are of greater or less importance according to circum- 

 stances. They have generally the character of local inflammatory 

 affections, the causes of which are naturally found in the combination 

 of the commencing pressure with the still slowly progressing motion. ^ 

 The serious extent to which these inflammations may increase is 

 shown not only by the instance we have given of acute Cestodic tuber- 

 culosis in the ox, but also by the constancy with which our experi- 

 ments with Coenurus produced in three weeks an inflammation in the 

 brain of the sheep, which was usually fatal. ^ When the skull is opened 

 in such cases, streaks of caseous exudation, about an inch in length, 

 are seen on the surface of the brain (Fig. 81), marking out the path 

 of the parasites and identified by the character of their surroundings 

 as the centres of the inflammatory processes — (Haubner, Leuckart, 

 van Beneden). 



FiQ. 81. — Brain of a lamb with tracks of Ccenurus. 



These local phenomena are of course not equally dangerous in all 

 organs. I have frequently seen the livers of rabbits which had been 

 fed with Tcenia serrata crossed and riddled by hundreds of youn" 

 Cysticerci (Fig. 82, see also p. 70), and yet I do not remember a single 

 case of death resulting from these disturbances.* As soon as the 

 worms have slowly wandered out of the liver, that is to say in the 



^ Comptes rendus, t. xxxiv., p. 9, 1852. 



' There is no doubt that the continuous pressure of the growing worm often of itself 

 gives rise to inflammatory processes ; so that it is sometimes impossible sharply to 

 distinguish the effects of simple pressure from those caused by the motion of the parasites. 



° This inflammation of the brain is somewhat incorrectly called " staggers " by some 

 investigators, but the characteristic symptoms of the latter disease do not appear until 

 some months after infection. 



* Compare with this the plates in my work " Blasenbaudwiirmer," p. 124, Part i., 

 Figs. 1-3. 



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