31 



dung of the diseased sheep, whether the granules have escaped or 

 not, and whetlier they are to be found in the pasturage of those lo- 

 calities, where the entozoon is sometimes known to be propagated 

 90 quickly as soon to infect entire flocks of sheep. 



" I could never see anything like a small fluke in the outer cyst, 

 at any period of its growth, although the operculum was often ob- 

 served just ready to open and give exit to its contents, as above de- 

 scribed. 



" The granules may possibly be regarded as yolk-globules, in 

 which case I apprehend the numerous secondary cysts, or cells, must 

 be considered as so many difterent yolks . 



" On the oval Corpuscles of the Cysticercus. 



" If the opake part near the head of this entozoon be gently 

 pressed, a little rather viscid fluid will escape, which on examination 

 will be found to be pervaded by a great number of oval corpuscles, 

 presenting a very beautiful microscopic object. They have a re- 

 markably distinct dark outline, with a brilliant surface, semitrans- 

 parent, and apparently homogeneous, except very rarely, when they 

 appear to contain an inner corpuscle or cellule. 



" They are generally but slightlj' oval, their length often scarcely 

 exceeding their breadth by a third, as exhibited in the drawing, 

 though they may occasionally be seen nearly twice as long as they 

 are broad. A common size of the corpuscles is about fj^o^^ ^^ ^"^ 

 inch long, and g owu^^ broad. 



" The bladder-like body of these hydatids is everywhere pervaded 

 by distinct spherules, presenting a bright oil-like appearance, vary- 

 ing in diameter from g^ouTTo*^ '-^ ^^oV o*'^ °^ '^'^ inch. Tliey have no 

 resemblance whatever to the oval corpuscles. 



" Hydatids are described as being without discernible generative 

 organs. Whether the remarkable oval corpuscles shown in the 

 drawing be ova or gemmules, must be determined by future obser- 

 vation. That they are the former appears probable, from their form 

 and general regularity of size. Besides they are situated in one 

 particular part of the parent, never appearing in the walls of the 

 transparent sac. If this conjecture should be confirmed, the cysti- 

 cercus can no longer be regarded as destitute of any distinct gene- 

 rative organ, for the part in which the ova are contained will corre- 

 spond to the uterus of the higher entozoa, and probably lead to a 

 further knowledge of the method by which the difl"erent species of 

 this genus are propagated. 



" I am indebted to the kindness of Mr. Siddall for the accompany- 

 ing drawings, which have been made by the aid of the camera lucida. 

 As they were taken from dried specimens, the internal structure of 

 the ova of the Distoma is not well exhibited, though the form is 

 faithfully shown." 



Mr. Lay exhibited a small Bird's Nest from Borneo, and a species 

 of Ateuchus from China, together with the ball which it forms for the 

 protection of its eggs. He also made some remarks on a species of 

 Gobiocephahts, found in the Sea of Japan. 



