GENERAL BIOLOGY 



carefully near the center of the cell and find the nucleus, sur- 

 rounded by a thin layer of the cytoplasm. 



5. Add all of these parts to your drawing. 



6. Asexual reproduction : Examine a number of filaments 

 carefully to see whether there is evidence of recent multiplication 

 by transverse division of some of the cells. Draw. 



7. Sexual reproduction : Examine, with low power, a stain- 

 ed and mounted preparation which shows two filaments in process 

 of conjugation. Study with high power and draw as many stages 

 in the process of conjugation as can be found, including the fully 

 formed zygotes. 



PROTOPHYTA 



One-celled plants in which the entire body consists of a single 

 cell, which may be independent or may be joined with others to 

 form a colony. 



SPHAERELLA (HAEMATOCOCCUS) 



(Protophyta, Flagellatae, Division Thallophyta, Subdivision Algae, 

 Class-Chlorophyceae. ) 



Read: Parker, Elementary Biology, pp. 23-35; or 

 Parker, Practical Zoology, pp. 240-250; or 

 Woodruff, Foundations of Biology, pp. 30-38. 



A. RESTING STAGE. 



(i). Spread out in water some sediment containing Sphaerella, 

 put on a cover glass, and look with low power for red or green 

 spheres. Having found one examine with high power and note: 

 (a). Size, variable; draw several to scale, 

 (b). Form ; spheriodal. 



(c). Structure; a sac surrounding the contents, which 

 latter consist of protoplasm, chromatophores, a 

 nucleus and sometimes a vacuole. 

 (d). Color; red, green or partly one and partly the 



other. 



Where is the coloring matter always situated? 



(2). Place a drop of iodine solution on the slide at the edge 



of the cover glass, apply a bit of blotting paper at the other side, 



thus drawing the iodine solution under the cover. What parts 



stain? How does it affect the nucleus and the chromatophores? 



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