8 MORPHOLOGY OF INVERTEBRATE TYPES 



particles, macronucleus. Label anterior and posterior end, 

 dorsal and ventral surface. 



2. Find under low power a specimen in the process of division. 

 Examine it at 200 diameters and make a drawing showing as 

 many structures as are visible. 



3. If possible, try to find a couple of Paramaecia in conjugation 

 and make a drawing of them. 



4. Take another drop of the same infusion, put a drop of the 

 methylgreen solution in i% acetic acid on a cover glass, turn the 

 cover glass over, so that the drop will be suspended from the 

 underside and allow the cover glass to drop suddenly on the 

 drop of hay infusion from a height of about one inch. This will 

 fix the animals and stain the nucleus after a while. Examine 

 under high power (400 diameters) and make a drawing showing 

 all structures brought out by the stain. 



5. Examine the prepared slide under high power (400 di- 

 ameters) and make a drawing showing trichocysts, macronucleus 

 and, if visible, micronucleus. 



6. Examine the prepared slide with Paramaecia in division 

 under high power (400 diameters) and make a drawing of it. 



7. Examine the prepared slide of Paramaecia in conjugation 

 under high power (400 diameters) and make a drawing of it. 



8. Additional exercise. Place a drop of water from the side of 

 an aquarium on a slide, add a small drop of quince seed jelly, 

 cover with a cover glass and examine under low power (100 di- 

 ameters) . Find as many species of Protozoa as possible, examine 

 them one after the other under high power (400 diameters), 

 identify them with the aid of a proper book and make drawings. 

 Label Class and Order to which the species belongs. 



9. Additional exercise. Take a drop of water from the bottom 

 of the aquarium with some sediment and do as in the preceding 

 exercise. 



10. Additional exercise. Cut off with fine scissors the head and 

 the last abdominal segment of a mealworm (larva of a beetle, 

 Tenebrio molitor). Take the end of the protruding alimentary 



