148 BOTANY. 



room for a few days, when various moulds will begin to develop. 

 Under favorable circumstances black mould will predominate. It 

 can be told by its dark color and the minute round black spore-cases 

 on the ends of the erect hyphse. Mount a few hyphge (as directed in 

 e above) and examine hyphse, spore-cases, and spores. 



(g) Moisten a piece of perfectly fresh bread, and then sow here and 

 there on its surface a few spores of black mould ; cover with a tum- 

 bler or bell-glass. In a few hours a new crop of Black Mould will 

 begin developing. 



(A) The more common black moulds, Mucor mucedo, M. racemosus, 

 and Ascophora mucedo, are common on many decaying substances. 

 Syzygites aspergillus occurs on decaying toadstools and other large 

 fungi. Hydrogera obliqua and Chsetocladium jonesii occur on ani- 

 mal excrement. Phycomyces nitens grows on oily or greasy sub- 

 stances, as old bones, oil-casks, etc. 



{i) Place several clean glass slides in contact with a culture of 

 black mould, as described in (g). By removing these at different 

 times the various stages of growth of the mould may be easily 

 studied. 



(j) In the latter part of summer and in the autumn examine the 

 dead flies which adhere to window-panes, door-casings, and especially 

 to wires and strings hanging from the ceiling. The whitish powder 

 around the fly will indicate the presence of the fly-fungus. Mount 

 some of this white powder in water and examine under a high power. 

 Tear out small bits of the distended abdomen of the fly, and examine 

 for internal portions of the parasite. 



(k) In the autumn look for dead grasshoppers attached to the tops 

 of weeds and grasses. Examine their interior tissues for thick-walled 

 resting spores of Entomophthora grylli. 



(I) For future study in the laboratory the aquatic Con jugatae should 

 be preserved in bottles of water containing just enough alcohol, 

 glycerine, or carbolic acid to prevent their decay. One fourth or fifth 

 of the first and second, and enough of the last to give a decided odor, 

 will usually do well enough. 



Systematic Literature. — Wolle, Desmids of the United States. 

 Wolle, Diatomacese of North America. Wolle, Freshwater Algae of 

 the United States. Saccardo, Srlloge Fungorum, 7', Flora of 

 Nebraska, 1. 35-53. pi. 6-11, U, 15. 



Order 5. SIPHONEJE. The Green Felts. 

 262. The plant-body in this important and interesting 

 order is a branched filament, in which the protoplasm is 

 continuous. These plants are, however, not to be consid- 



