GENERAL BIOLOGY 



acid, and also with a bubble of carbon dioxide. Place animals in a 

 tube heated at one end and cooled at the other. What results ? In 

 a similar manner test them with the electric current. Also test their 

 sensitivity to light and gravity. Record all of your results. 



IV. AMOEBA PROTEUS. 

 (Phylum Protozoa, Class Sarcodina, Order Rhizopoda.) 



Read: Calkins, Biology, pp. 44-59; or 



Parker, Elementary Biology, pp. 1-22; or 



Parker and Parker, Practical Zoology, pp. 229-238 ; or 



Sedgwick and Wilson, General Biology, pp. 158-167. 



Place a small drop of sediment from a vessel containing Amoeba 

 on a slide with a drop of water ; cover with cover glass and search 

 for Amoeba with low power. If not easily found, prepare several 

 such slides and examine them after they have been standing for 

 some minutes, so that the Amoebae may crawl out of the sediment. 

 When an Amoeba is found examine with a high power and note : 



A. MORPHOLOGY. 



1. SIZE; is it visible to the naked eye? 



2. SHAPE; is it regular? Constant? Are the pseudopodia of 

 the same size and shape? Do they ever branch? How many do 

 you find? Sketch at intervals of one 'minute for five minutes. 



3. STRUCTURE: An outer clear layer, the ectosarc (ectoplasm), 

 and an inner granular more opaque substance, the endosarc (endo- 

 plasm). Is the boundary between the two layers a sharp one? 

 Where is the ectosarc thinnest ? Is there a membrane outside this 

 layer? Are all the granules of the endosarc of the same size? 

 Which layer is the more fluid ? In the ectosarc a clear vesicle may 

 be found which appears and disappears; this is the contractile 

 vacuole. How long does it take to contract, how long to expand? 

 Are there any visible contents ? Is there more than one contractile 

 vacuole ? 



In the endosarc a round, clear body may be found, which does 

 not change shape; this is the nucleus. Is it more solid than the 

 surrounding protoplasm? What is its shape? Size? Is it always 

 in the same place? There are often also in the endosarc various 

 foreign bodies which serve as food, such as diatoms, desmids, 

 green cells, etc. Draw to show structure. 



4. Stained Specimens : In a prepared specimen, stained and 

 mounted, observe nucleus, ectosarc, indosarc, etc. Draw. 



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