XXVI EXPLANATION OF THE PLATES. 



d. Fourth stage. 



Fig. 5. Small portion of the germinal membrane of Acephalocystis 

 armatus. 



Fig. 6. Small portion, highly magnified, of the granular matter from 

 the cyst of Cysticercus. 



Fig. 7. Small portion of the inner surface of the external membrane 

 of Acephalocystis armatus while in a state of degeneration. 



Fig. 8. Ovum from the pedicle of Cysticercus. 



Fig. 9. Small portion of the germinal membrane of Acephalocystis 



monroii, highly magnified. 

 a. Fibrous basis. 

 6. Germinal vesicles. 



c. Secondary acephalocysts within the germinal vesicles ; this 

 portion was taken from the large parent cyst, which is the 

 primary animal, buried in the liver ; and each of the smaller 

 vesicles marked c belong therefore to the secondary genera- 

 tion, their progeny again being the tertiary generation. 



Fig. 10 Is a specimen of Cysticercus neglectus ruptured at the fundus of 

 the sac, apparently for the escape of the young germs into 

 the cavity of the cyst, where they become attached. 



Fig. II. Small portion of the cyst of Cysticercus neglectus magnified, 

 showing its vascularity, and the mode of attachment of the 

 young Cysticerci to its internal surface. 



Fig. 12. View from above the pedicle of Cysticercus, showing the dis- 

 position of the teeth. In all works hitherto published on 

 Helminth ology, there has been a great want of proper figures 

 or descriptions of the true generic and specific characters of 

 these animals, a point of the utmost importance for obtaining 

 a proper knowledge of them : with this view the author has 

 paid scrupulous attention to the leading characters, and these 

 he has placed in the form of a synopsis at the end of the 

 chapter. All the drawings have been made with the view of 

 illustrating these characters more fully. The disposition of 

 the teeth, and their forms, are perhaps the most certain ex- 

 ternal characters. 



PLATE XI. page 482. 



Fig. 4. Magnified view of a small portion of the external or tubular 

 membrane of Diskostoma acephalocystis. 



a. Larger disc. 



b. Smaller one on its surface. 



c. Tubuli. 



d. Extremities of tubes. 



e e. Gemmules, which at this stage of development may act as 



absorbents. 



Fig. 5. Natural size of Diskostoma acephalocystis. 

 Fig. 6. Diskostoma acephalocystis in various stages of development. 



