PART II.-ANIMALS 



LABORATORY EXERCISES 



I. Organization of Animals 



90. Protozoa: 



(a) Observe an actively moving amoeba for some time and sketch its 

 outline five times to show the change of form. Trace in these 

 outlines the changes through which each pseudopodium passes. 

 Note the ingested food particles and, if possible, observe the 

 process of ingestion. Note the contractile vacuole. 



(b) In a stained preparation note the structure of the protoplasm, 

 the nucleus, the contractile vacuole and the food vacuoles. 



91. (a) Study the movement of a ciliate protozoan (Paramecium). How 



many kinds of movement does it perform. 



(b) Study a living individual under higher magnification. Note the 

 cilia, the buccal groove leading to the mouth, the food vacuoles 

 and the contractile vacuoles. 



(c) In a stained preparation note the macronucleus and the micro- 

 nucleus. 



92. Ccelenterata: 



(a) Observe a living hydra in the aquarium, first with the unaided 

 eye then with the lens. 



(b) A hydra (living or a fixed preparation) which shows reproduction 

 by budding. 



(c) Preparations of hydra to show the gonads. 



(d) A cross section of the body to show ectoderm and endoderm. 

 Note the muscle fibrils which show as dots between ectoderm 

 and entoderm. Also the central gastro-vascular cavity. 



93. (a) A hydroid colony (Obelia) (Pennaria). Sketch the colony. 



Compare a polyp with hydra. Is there evidence of budding? 

 (b) A hydrozoan medusa (Obelia). In a stained preparation note 



the manubrium and mouth, the radial canals, the gonads, the 



tentacles and the velum. 

 (b 7 ) The medusa of Gonionemus is larger than that of Obelia and may 



be studied with the lens. 



