402 APPENDIX. 



(See TT 25.) When conjugating it often loses the deep green and 

 becomes yellowish, and the filaments seem to be double. 



This condition can be recognized under the lens. Spirogyra 

 may often be obtained all through the year in pools and springs. 

 It should be preserved in the following solution: Camphor water 

 50 cc; water 50 cc.;* glacial acetic acid 0.5 cc; copper nitrate 

 2 gm.; copper chloride 2 gm. 



Cladophora. — Species of this genus may be found attached to 

 sticks and stones at the edge of lakes or pools. It often covers 

 these completely with a thick mat of long, yellowish green, 

 branched filaments. It may be found throughout the growing 

 season. For winter use preserve in same solution as above. 



Chara. — Several species are common in shallow ponds and lakes, 

 in water 0.2-1 meter deep, rooting in the mud, often in company 

 with Myriophyllum and Ceratophyllum, two seed plants, the latter 

 of which may readily be mistaken for it by novices. But these 

 plants are usually bright green while Chara is dull or dirty green, 

 or even whitish (especially when dry) from the coating of lime, 

 which also renders it brittle and harsh to the touch. Careful in- 

 spection of its form and a section of the axis at once enables one 

 to recognize it. (See figs. 35. 37.) Specimens should be gathered 

 when the spermaries on the lower branches (" leaves ")are orange. 

 Pull up the plants carefully, wash off as much as possible of the 

 mud which clings to the delicate, colorless rhizoids. The basal 

 part of the axis should be put in a separate jar from the rest. 

 Put a few plants into 2 per cent, chromic acid, and allow them to 

 remain 24 hours to dissolve off lime with which they are incrusted. 

 After pouring off the acid and rinsing them thoroughly, soak 

 them in a large vessel of water for 24 hours, changing water 

 several times (or allow water to run over them slowly for six 

 hours) to remove acid. Preserve in 70 per cent, alcohol. Plants 

 may be preserved in formalin or 70 per cent, alcohol, in long 

 jars so as to entangle them as little as possible. If brittle from 

 alcohol (as they often are) before removing them from jar for 

 distribution pour off alcohol and cover with water for a few 

 minutes. 



Polysiphonia. — All species are marine, and any common species 

 will serve. They are found in reddish brown, feathery tufts 2- 

 10 cm. high, on other larger sea-weeds, or on piles and stones, 

 about low-water mark. They collapse completely when with- 

 drawn from the water. 



