60 MORPHOLOGY OF INVERTEBRATE TYPES 



leading to the outside, (2) the opening of the penis, (3) the open- 

 ing of the common oviduct, (4) the opening of the uterine canal 

 and (5) the opening of the bursa copulatrix. 



The cocoon in which the eggs are inclosed is formed in the case 

 of Dendrocoelum lacteum in the genital cloaca. The develop- 

 ment is direct. 



Instructions 



1. Make a half page drawing of a live or preserved specimen 

 showing the shape of the body, tentacles, median lobe, eyes, 

 alimentary canal, mouth, genital cloaca and the common genital 

 opening. 



2. Place a live specimen on a slide in a drop of water under 

 cover glass and examine the edge of the animal under high power 

 (400 diameters). If the light is adjusted correctly the beating of 

 the cilia of the epithelium will be observed without diffi- 

 culty. 



3. Make a drawing from a prepared slide of a cross-section 

 through the region of the eyes. Label eyes and brain. 



4. Make a drawing of a cross-section through the region 

 of the ovaries. Label ovaries and stomach with its 

 branches. 



5. Make a drawing of a cross-section through the region 

 somewhere between the ovaries and the pharynx. Label epithe- 

 lium, muscular system, testes, oviducts, yolk glands, anterior 

 stomach canal with its branches, longitudinal nerves and 

 parenchyma. 



6. Make a drawing of a cross-section through the region of 

 the pharynx. Label all organs including the vasa deferentia, 

 mouth cavity, pharynx, and pharyngeal glands. 



7. Make a drawing of a cross-section through the region of 

 the uterus and label parts. 



8. Make a drawing of a cross-section through the region of 

 the penis pouch and label parts. 



