APPENDIX. 



COLLECTION AND PRESERVATION OF MATERIAL. 



Spirogyra may be collected in pools where the water is pres- 

 ent for a large part of the year, or on the margins of large 

 bodies of water. To keep fresh, a small quantity should be 

 placed in a large open vessel with water in a cool place fairly 

 well lighted. In such places it may be kept several months in 

 good condition. 



Mucor may be obtained by placing old bread, etc., or horse 

 dung, in a moist covered vessel. In the course of a week there 

 should be an abundance of the mycelium and gonidia. From 

 this material cultures may be made, if desired, in nutrient gela- 

 tin or nutrient agar. 



Saprolegnia, or water mould, can be used for a study of pro- 

 toplasm. Collect several dead house flies from window sills of 

 neglected rooms. Immerse them in alcohol, then rinse in 

 water to remove the alcohol. Then throw them in vessels of 

 water containing freshly collected algae from several different 

 places. In the course of a week there should be a tuft of whit- 

 ish threads of the water mould surrounding the fly. 



Nitella is obtained in rather deep pools or ponds, or in slow- 

 running water, at a depth of one to three feet usually. 



Stamen hairs of tradescantia can usually be obtained in 

 greenhouses from flower buds just ready to open or just after 

 opening. 



(Edogonium is often found in floating mats in ponds, or on 

 the margins of slow-running streams, or of lakes. Frequently 

 it is attached to other aquatic plants. Fruiting plants can be 



... 713 



