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GUIDE TO THE STUDY 



crustaceans. Here it develops into a first larval stage, and 

 when the infected crustacean is devoured by pike, pickeral, 

 burbot, and certain other fish, the larva develops into an elongate 

 wormlike plerocercoid encysted in the muscles. In this stage 

 it is infective to man. 



Make sketches of a mature segment, a scolex, and eggs, 

 showing the above features. Plerocercoids of this or related 

 species will be demonstrated. 



Multiceps serialis (Gervais) is a tapeworm of dogs which 

 in its morphology closely resembles Tcenia pisiformis. In its 



p IG 11 — A cyst of Multiceps srrialis from the shoulder of a jack-rabbit. 

 Each of the rounded white bodies is a head capable of developing into a tapeworm 

 if ingested by a dog. (Orig.) 



development in the intermediate host it presents a striking depar- 

 ture from the usual type. The cysts (Fig. 11), occur as large, 

 so-called "boils" in the muscles of rabbits. They are filled 

 with a limpid fluid, and on the interior are great numbers of 

 minute granular bodies, each of which represents the invaginated 

 head of a future tapeworm. In other words, worms of the genus 

 Multiceps exhibit polyembryony, or the production of many 

 individuals from a single egg. Examine demonstration speci- 

 mens of the cysts in situ, and study prepared slides showing the 

 invaginated scolices. 



Echinococcus granulosus (Goeze) is the dangerous hydatid 

 tapeworm which develops its cystic stage in a wide range of 



