88 BOTANICAL GAZETTE [AuGuST 
they appear as black points in the white mycelium. At times 
there is a pink pigment developed, which gives color to the 
acervuli. In subsequent transfers to bean stems, in which the 
mycelium was less abundantly developed, the pustules showed 
a considerable formation of stroma, and sete were distinctly 
seen, although their presence is quite variable. 
COLLETOTRICHUM LAGENARIUM (Pass.). Sacc. and Roumg. 
( figs. 17, 18, 62-69, 75-79); on watermelon (Citrullus vulgaris). 
In Farlow’s host index this species is recorded for the fol- 
lowing cucurbits; watermelon (Citrullus vulgaris), muskmelon 
( Cucumis melo), cucumber (Cucumis sativus), pumpkin ( Cucurbita 
pepo), and squash (Cucurbita sp.). 
Its presence is indicated by subcircular brown spots on the 
rind of the watermelon; on some spots the tissue at the margin 
may become black, or the order may be reversed and a 
dark center may be surrounded by a lighter brown portion. 
Dull roseate acervuli rupture the epidermis, and are arranged 
more or less concentrically, The presence of setz is a variable 
character ; in some pustules which were quite mature none could 
be detected even in carefully prepared microscopic sections. 
This has led to some confusion in the history of the fungus as 
to its generic position. The conidia are rather long, narrowly 
elliptical, 16-20 x 4-54, sometimes ovate-oblong or inequi- 
lateral. 
A section through the pustule shows but a slight develop- 
ment of basal stroma; the basidia are rather long, immersed, 
but extending partially above the surface of the host. 
The fungus does not adapt itself readily to artificial cultures, 
and several unsuccessful attempts were made before satisfactory 
results were obtained. Conidia sown in meat-agar were seen to 
germinate, but subsequent growth took place slowly, and the 
contents showed disintegration. The mycelium became coarsely 
granular, and the contents showed disintegration. More satis- 
factory results were obtained in potato-agar, but here, also, the a 
growth, as well as on bean stems, made but little progres® « ee 
