52 THE BIOLOGY OF THE CELL 



of the material to a jar of fresh water. Under such 

 conditions of cultivation the plants will go through 

 their fruiting stages nearly all winter. If it be imprac- 

 ticable to keep living plants for study, specimens may 

 be preserved in fair condition, though the color will be 

 lost, in a mixture of equal parts of water, glycerine, and 

 alcohol. 



The following study requires the use of the hand- 

 lens, compound microscope, fine forceps, seventy-five per 

 cent, sulphuric acid, Schulze's solution, dilute iodine, pi- 

 cric acid, strong potash solution, ninety per cent, alcohol, 

 carmine, magenta, two per cent, salt or sugar solution, ten 

 per cent, salt or sugar solution, twenty per cent, salt or 

 sugar solution, a vial or test-tube, distilled water, Sachs's 

 food-solution, ice, and a saucer. 



Method of Examination. — The plants should first be 

 studied in their native pool, their surroundings and hab- 

 its noted, etc. Then examine some as they grow in an 

 aquarium. Then, with the forceps, transfer one or two 

 filaments to a porcelain bowl or saucer in which the 

 dark green of the plants will show weU against the 

 white background formed by the saucer. For the mi- 

 croscopic study only two or three filaments should be 

 placed on the slide, where they may be studied with 

 the hand-lens and with both low and high powers. 



MOEPHOLOGT 



A. — Yegetabive Condition. 

 I. Naked-eye characters. 



Examine some of the plants as they grow in 

 the aquarium, particularly the position occupied 

 by the mass after exposure to sunshine for a few 



