6o 



GENERAL BIOLOGY 



The two studies which immediately follow are intended 

 to give i) an acquaintance with the appearance of the living- 

 part of plant substance, and 2) some knowledge at first 

 hand of the diversity of form of cells and 

 of the manner of their combination to- 

 gether into a plant body among the algae. 



Study 8. The cell of Spirogyra and the 



protoplasm of Nitella. 

 Materials needed a supply of fresh 

 Spirogyra and Nitella in clean water. 



Apparatus needed the usual labora- 

 tory equipment of simple and compound 

 microscopes, small tools, glassware and 

 reagents. 



The student should first examine Spir- 

 ogyra in mass, as it lies in the water, and 

 then lift out a small tuft of its long 

 filaments for examination in water upon a 

 a white plate. He will there note their 



Fl S;ab 4 itof S a P fiiame r nt length and their unbranched condition. 

 Examining them with a simple lens, he 

 ; wil1 be able to distinguish clearly the 

 "- s P iral bands of S reen tha t wind about each 

 phyi band. filament on the inside and make Spirogyra 



easy of recognition among other algae of similar manner of 

 growth (fig. 44). 



If he then mount a few filaments upon a slide, placing a 

 cover-glass upon a favorable portion, and filling up the 

 space beneath the cover glass with water, he may with 

 advantage apply the compound microscope to the ex- 

 amination of them.* Placing the slide thus prepared 



*If the student be not familiar with the use of the compound 

 microscope, let him at this point pursue the supplemental study 

 outlined in the opening pages of the appendix, for which Spirogyra i 

 appropriate material. 



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