DoDGE : METHODS OF CULTURE OF ASCOBOLACEAE 151 
studies of such species as Ascobolus viridis, A. pusillus, and A. 
carbonarius, all of which grow on the ground rather than on the 
excrement of animals, repeated visits to the same spots for three 
successive years were made and the condition of the species under 
various weather conditions was noted. Apothecia in all stages 
of growth were brought into the laboratory and their diagnostic 
characteristics were worked out in detail. For laboratory cultures 
on the natural substratum, earth and dung were brought in and 
placed in damp chambers of glass lined with filter paper. 
Some species are very minute, and the apothecia are frequently 
so few that their detection is a matter of difficulty. The Zeiss 
binocular with the horizontal arm is a very useful instrument for 
this work. With the higher powers, and a damp chamber pro- 
vided with a flat cover, it is possible to study the development of 
the plants, their heliotropic reactions, and the discharge of the 
spores under very normal conditions. 
The apothecia seem to develop best when the cultures are 
carried on in a well lighted room having a temperature of about 
we ay CC, Tn‘a dimly lighted or cold room there are usually 
marked changes in the coloration of the spores and fruit bodies. 
Ascophanus carneus when grown in bright sunlight will have a deep 
pink apothecium, but in a dimly lighted room the fruit body will 
be nearly colorless. The spores of A. Winteri that were allowed 
to develop in a closed vasculum were perfectly hyaline. When 
this species is grown in a cold room or is found in nature during 
cold rainy weather, the spores are much paler than usual. 
In order to determine whether certain species were limited in 
their cccurrence to a particular kind of dung, extensive studies 
were made of the species growing on dung from the New York 
Zoological Park. So far as could be learned, most of the species 
‘are not thus limited. 
The following species have been grown on their natural sub- 
Strata in the laboratory. Their identity has been determined by 
careful study and comparison with exsiccati at the New York 
Botanical Garden: 
Ascobolus aerugineus Fries 
Ascobolus 
Ascobolus 
As 
cobolus Surfuraceus Pers. 
Ascobolus glaber Pers. 
carbonarius Karst. Ascobolus immersus Pers. 
- Ascobolus Leveillet Bouc. 
