28 A TAPEWORM. 



Technical Note. Snip off the scolex, including a few of the indistinct 

 proglottids that immediately follow it. Mount on a slide and examine 

 first with a low power of the compound microscope. For the finer 

 detail it will be necessary to use a higher power and to withdraw some 

 of the water from under the cover-slip so as to compress the mount 

 somewhat. 



c) After examining again the hooks and suckers, look for some fine 



transparent tubes coiled about in the scolex. These are excretory 

 canals. Other ramifications of the excretory tubes will be noted in 

 the individual proglottids. The finer branches of the system end in 

 the so-called flame cells. Some of these, each with its flickering, 

 vibratile cilium, may be made out, in the living specimen, by focus- 

 ing sharply on the more transparent portions of the scolex. 



d) Observe the large number of minute, round calcareous granules. 

 Exercise 2. Draw the scolex, very much enlarged, showing any detail that 



can be clearly made out. 



Technical Note. Mount stained specimens of proglottids in balsam or 

 dilute glycerine and cover with a slip heavy enough to compress with- 

 out crushing. If not convenient to stain, good results may often be 

 obtained by first soaking the specimens a while in a solution of caustic 

 potash and then in one of equal parts glycerine and water. The 

 proglottids for this study should be selected from the body about one 

 third way back from the scolex, as those nearer the posterior end are 

 too much distended with eggs. 



e) There is no digestive system, no body cavity, and no circulatory 



system hi a tapeworm. The reproductive organs constitute the 

 bulk of the organism. Along with certain muscle fibers they are 

 imbedded in a spongy tissue, the parenchyma. 



f) Running the entire length of the body, near each lateral margin, 



and continuous from proglottid to proglottid, is a longitudinal 

 nerve and one or two main tubes of the excretory system referred 

 to in the study of the scolex. These nerve cords and excretory 

 tubes sometimes have transverse commissures or transverse 



