386 BOTANICAL GAZETTE [JUNE 
hydrate and tartaric acid weighed out in the dry form and added 
to the prune juice in the proper amounts; the following series of 
flasks were made up: 7, 3, I, 2, 3, 4, 5, and 10 per cent. acid, 
with similar alkaline series. 
With Botrytis no results affecting the main question were 
obtained from these cultures. After four days good mycelium 
and conidia had developed in alk. ;4, per cent., neutral, and +, 
3, and I percent. acid. Acid 2 per cent. had considerable myce- 
lium, rather dense, and a few conidiophores. Acid 3, 4, and 5 
per cent. had a smaller amount of dense mycelium, forming a 
compact membrane. Acid 10 per cent. had merest trace of 
development. Alk. } per cent. had good mycelium, loose and 
flocculent, with some conidiophores around the edges. Alk. 1 
per cent. about the same but with very few conidiophores. Alk. 
2 per cent. poorer mycelium with woolly, flocculent appearance 
and no conidia. Alk. 3 per cent. merest trace of development. 
Alk. 4, 5, and 10 per cent. no growth. Two weeks later conidia 
were abundant in all the acids except the IO per cent., which 
showed no growth. The alkalies had quite abundant conidia 
below 3 per cent., but from there on very little or no develop- 
ment. Acid 1 per cent. gave about as vigorous and typical a 
Botrytis growth as any. The contrast was very marked between 
acid 2~5 per cent. and alk. 1-2 per cent. The former formed a 
close dense membrane, while the latter was loose, woolly, and 
flocculent. No particular difference in the filaments could be 
seen with the microscope. While these results have some little 
general interest they gave no evidence as to a connection between 
Botrytis and other “drop” fungi. The no-botrytis fungus with 
small sclerotia showed no such striking differences in develop- 
ment in acid and alkaline media as did Botrytis. Its range of 
growth was about the same and the effect upon the mycelium 
was somewhat similar but by no means as marked. From one 
culture of this sort, however, a valuable result was obtained. 
This was a large flask of prune of considerable alkalinity but not 
made up in definite proportions. It was inoculated with myce . 
lium from a pure culture of the small-sclerotia fungus, coming 
