CCENURUS. 



117 



This malady has likewise been called sturdy, turnsick, goggles, 

 and vertigo. The Coenurus, as previously stated, is now known 

 to be the larva of a species of tapeworm {Tcenia coenurus) in- 

 festing the dog. At an early date it had been described by 

 Gmelin and Goeze as a T^nia {T. cerehralis of the former and T. 

 vesicularis of the latter). Until recently it was supposed that this 

 kind of cestode larva only inhabited the brain, being also con- 

 fined to the herbivora. I have, nevertheless, discovered another 

 kind of Coenurus, infesting the lungs and liver of a Madagascar 

 Lemur, occasioning this animal's death by atrophy of the organs, 

 and consequent denutrition of the entire body. Mr. Rose had like- 

 wise previously discovered a Coenurus beneath the skin of the rabbit. 

 The brain-hydatid of the sheep, as commonly met with, varies 

 in size from a pea to a pigeon's egg, but occasionally it exceeds 

 this bulk, and (when it happens to occupy the spinal canal) 

 may acquire a length of upwards of a foot.* Ordinarily, it is a 

 simple bladder-like vesicle, distended by a clear, pale-yellow, albu- 

 minous secretion, displaying on its outer surface a great num- 

 ber of retractile papillae. These small elevations, when microsco- 

 pically examined, are found to be tapeworm heads connected by 

 narrow stalks to the common vesicle supporting the colony. 

 The stalks, in fact, are short, cylindrical tapeworm-bodies, their 

 transverse markings representing a series of future proglottides 

 in their most rudimentary form. Protruded to their fullest extent, 

 these young tapeworms (scolices) measure fully \ of an inch in 

 length, the transverse diameter of the head being about y^ of 

 an inch. When highly magnified the conical heads exhibit a pro- 

 minent, pointed rostellum, armed with a double coronet of hooks, 

 and four large suckers situated at the equatorial margin immedi- 

 ately beneath. The coronet is made up of two sets of hooks which 

 may be easily distinguished by their size, and also by the circum- 



* Leuckart informs me that he has an example of this kind in his private collection. 

 Numan describes and figures a similar specimen in his elaborate monograph, " Over den 

 veelkop-blaasworm der hersenen.'" Plate iv. fig. 1. 



