110 TYPE STUDIES 



THE SAC FUNGI, OE ASCOMYCETES 



110. Field work on the sac fungi and basidia fungi. The groups of higher 

 fungi, Ascomycetes and Basidiomycetes, may readily be studied together in 

 the field, since representatives of both are usually found in the same situa- 

 tions. There are several sorts of localities vrhich furnish abundant supplies. 



(1) Wet, shaded vfoods and the borders of shaded swamps will give the 

 larger forms of cup fungi and their relatives, and certain basidia fungi. 



(2) Open woods, especially along woodland paths, are excellent situations 

 for the fleshy gill, pore, and tooth fungi, while stumps, logs, and fallen 

 branches furnish material of the woody basidia fungi and the knot and wart 

 fungi. (3) Pastures and the edges of woodland are favorable situations for 

 certain gill fungi and puffballs. (4) Lichens grow under a great variety of 

 conditions, from those of bare soil and rocks to much shaded situations on 

 tree trunks. (5) The parasitic forms have for the most part their own 

 peculiar life habits associated with various hosts. Collections of conspicuous 

 forms should be made with careful notes on the life conditions, and the forms 

 brought to the laboratory for identification, at least so far as the chief groups 

 are concerned. The woody and firm fungi (including lichens) and many 

 parasitic forms on leaves may be dried or pressed as one would any plant. 

 Fleshy fungi must be preserved in strong alcohol. 



111. Microsphaera, the lilac mildew. Study its habit of growth 

 on the lilac. Where is it most luxuriant ? Describe the appear- 

 ance of the mycelium on the leaves. Try to find leaves that 

 appear powdery because of the conidial fructification, commonest 

 in the summer time." Note the position of the ascocarps or sac 

 fruits, appearing as black dots. 



A. The ascocarps. Sketch the outline of a leaf and show the 

 distribution of the mycelium with its ascocarps. Moisten the 

 surface with a dilute potash solution, and with a scalpel 

 scrape off some of the mycelium and sac fruits. 



1. Note the character of the hyphai, their branching, the 

 occasional cross partitions, and the cell contents. 



2. Draw an ascocarp with one or more of its appendages in 

 detail. What is the structure of the wall of the fruit and 

 the tips of the appendages ? Note the number, form, and 

 distribution of the latter. 



