EQUINE ENTOZOA. 335 



Cestode Epizooty. — This epizooty occurred among some 

 ponies in South Wales, and among the prominent sym- 

 jitoms were extension of the head, the animals appearing as 

 though suddenly distracted, rubbing the quarters, running 

 and rolling about for a few minutes, then getting up again, 

 and appearing to be well again. If coming down a slope 

 the animals would fall, and in some cases there was lame- 

 ness in one hind-leg. 



Source of the Tapeworms of the Horse. — The cystic forms 

 of taenia placata, taenia mamillana, and taenia perfoliata, are 

 as yet unknown. 



Probably their larval forms exist in the bodies of different 

 insects. 



Larval Forms of Taeniae. —Larval forms have received 

 various names, according to their contents, viz. : 



1. A Cystkercus is a cyst filled with serum, and provided 

 with only one head. 



2. A Coeimrus is a cyst filled with serum, and provided 

 with many heads. 



3. An EcUmcocciis is a primary cyst, which contains, or 

 which gives rise to, secondary cysts filled with serum, each 

 provided with numerous heads. 



LARVAL FORMS OF TiENlJE OF THE HORSE. 



The larval cestodes of the horse are, comparatively speak- 

 ing, somewhat rare. The one most frequently met with, 

 however, is that of the Taenia Echinococcus. 



1. ECHINOCOCCUS VETERINORUM.— This cystic worm 

 is the larval form of the taenia echinococcus, which infests 

 the small intestines of the dog and wolf 



The adult tapeworm is composed of four segments, or 

 joints, and is a little over a quarter of an inch in length. 

 The first joint includes the head, which is about jj^ of an 



