14 ELEMENTAEY BIOLOGY. [H- 



LABORATORY WORK. 



A. Morphology. 



a. Resting or stationary Protococcus. 



1. Spread out some of the green matter iu water, and 

 put on a cover-glass. Examine first with a low, and 

 then with a high power. Note the size, form, struc-. 

 ture, and colour of the cells. 



Size ; (measure) — very variable. 



Form ; more or less spheroidal, with individual varia- 

 tions. 



Structure; sac — protoplasm — sometimes a vacuole — 

 sometimes apparently a nucleus. (Compare 

 Torula, I. A. 2. h) 



Colour ; generally green^sometimes red — sometimes 

 half and half — sometimes centre red, periphery 

 green — the colouring matter always in the pro- 

 toplasm only — most frequently diffused, but 

 sometimes in distinct granules. 



2. Note especially the following forms of cell — 



a. The primitive or normal form,. . 



Roundish cells, with a cellulose sac, and unseg- 

 luented granular contents. Draw several carefully 

 to scale. Apply the methods of mechanical and 

 chemical analysis detailed for Torula. (I. A. 3. 4. 

 5. 6.) Note that iodine in some cells produces a 

 blue coloration (? starch). Treat a specimen with 

 iodine solution and then with sulphuric acid (75 

 per cent.) : the sac will become stained blue. 



