EUGLENA 83 



by starch, sugar, cellulose, oils, and fats ; and (2) the proteids, 

 which contain nitrogen, sulphur, and in some cases phosphorus, 

 in addition to carbon, oxygen, and hydrogen. The principal tests 

 for these substances and some characteristics of their appearance 

 are given in Part I as follows : (1) starch, Sec. 12, A; (2) sugar. 

 Sec. 12, B ; (3) cellulose. Sec. 12, C ; (4) oils and fats, Sec. 12, E ; 

 (5) proteids. Sec. 12, F. 



THE FLAGELLATES, OR FLAGELLATA 



67. Euglena (App. 9). Study its habits in a glass dish placed near a 

 window. Do the organisms congregate in any part of the dish ? Why ? 



A. Mount in a drop of water and examine under l.p. Describe move- 

 ments. Under h.p. study cell structure. Note and draw : 



1. The naked protoplast ; arrangement and form of the chloroplasts. 



2. A red pigment spot at the forward end. Can you suggest its pos- 

 sible function with reference to the behavior of the organism 

 towards light ? 



3. The structure of the forward end with a narrow, slit-like opening 

 leading into a cavity ; the position of a long, \m\v-\\\e flagellum, or 

 cilium. These structures will probably become clearer after staining 

 with iodine, as described in B. 



B. Drain off as much water as possible from under the cover glass and 

 then place a drop of iodine solution at the side. It will slowly diffuse 

 through the water, killing and staining the Euglenw. Watch and de- 

 scribe the effect. Draw details of the forward end, showing the flagel- 

 lum and the opening. 



C. Study Euglena in the encysted condition, when the protoplast is sur- 

 rounded by a protective wall. Search for examples of cell division 

 while in this condition. Draw. 



THE SLIME MOLDS, OR MYXOMYCETES 



68. The spore fruit of a slime mold. The fructifications of the slime molds 

 are certainly plant-like and have been studied and classified chiefly by bot- 

 anists. Such types as Stemonitis, ArcT/ria, Hemitrichia, and Lycogola are 

 favorable for study. 



A., Draw a habit sketch of the spore fruit. Note : 



1. The character of the attachment, whether or not stalked ; the spore 

 case. 



