BILHARZIA. 



78. Snails. Examine and draw the shells of the snails into which the miracidia bore 

 and in which they develop in Egypt. Bilharzia hsematobium only develops in Bullinus 

 and B. mansoni in Planorbis. Look at the demonstration of the living snails. In addition 

 draw an example of the shell of a right-handed snail for comparison with the left-handed 

 shell of Bullinus. 



79. Sporocysts and Cercariae. Examiiie the fresh preparation from the liver of an 

 infected snail. Draw a sporocyst, showing the contained embryos, and then draw the 

 successive stages in the development of cercarise, showing : two suckers ; forked gut ; 

 forked tail, 



