118 BNTOZOA. 



stance that they regularly alternate with one another, fifteen in 

 each row. The iategument consists of a fine external pellicle 

 enclosing a soft granular dermis, and subdermal parenchyma, in 

 which we detect an immense multitude of the so-called calcareous 

 corpuscles. The great vesicle itself shows a very diSferent structure, 

 being made up of six or eight layers of regularly-disposed cells, in 

 which neither vessels nor corpuscles can be recognized. Accord- 

 ing to Numan, both crystals and larvae are found in the fluid of the 

 sac, but I fear they must be regarded as pathological formations. 



Besides infesting cattle and sheep, the common Coenurus has 

 been found in the goat, in the horse, in various species of ante- 

 lopes and deer, in the dromedary, and also, it is said, in the rabbit. 

 In most of these animals it is Hable to give rise to a formidable 

 disease, the symptoms of which are found to vary considerably 

 according to the particular situation occupied by the parasite, 

 whether in the brain or spinal cord. In the sheep the disease is 

 recognized at first by a heavy, stupid, wandering gait, which is fre- 

 quently succeeded by irregular, tortuous, whirling movements of 

 the body, accompanied with convulsions. A simple temporary cure 

 is readily effected by puncturing the head over the diseased part, 

 but very commonly the animals die of exhaustion and inability to 

 take their proper amount of food. In the later stages of the dis- 

 ease, especially where several Coenuri exist in the same brain, it is 

 not uncommon to find the skull of the sheep thinned out in various 

 directipns. In many places the bony absorption is complete, so 

 that the skuU exhibits, on being dried, a perforated and irregularly 

 honeycombed appearance. 



The administration of fresh Coenuri to dogs has proved the 

 source whence these larv^ are derived, whilst, on the other hand, the 

 feeding of lambs with a particular species of tapeworm has demon- 

 strated whence the Tgenige are derived. Kuchenmeister, Haubner, 

 Gurlt, Roll, Eschricht, Leuckart, Van Beneden, and others abroad, 

 have repeatedly shown that the Coenurus of the sheep is the larva 

 of the TcBnia ccenurus normally infesting the dog, and their re- 



