154 



ZOOLOGY 



complicated series of stages to go through before it be- 

 comes adult. Thus the flukes in the liver of the sheep 

 produce eggs which develop into embryos. These em- 

 bryos get out of the liver into the food canal, and thence 



00' 



u 



ec.10. 



"J Marcti13.Apr.4-. 

 Jan.25. FAS. Feb.17 



Jec.W. 



Jan.25. 



Feb.5. 



FIG. 143. Showing results of cutting Planarians into two pieces; the pieces 

 develop into entire animals. After Morgan. 



to the exterior. If they are deposited near a pool of 

 water, they may develop further, otherwise they must 

 die. In the water a ciliated larva a hatches from each 

 egg, swims about for a time until it finds a fresh-water 

 snail, bores into it, and encysts itself there. In this 

 i Fig. 146, A. 



