4° BOTANICAL GAZETTE [JULY 
plied with abundant moisture. In my cultures of Funaria pro- 
tonemata on earth this manner of growth was very marked. The 
cultures were supplied with a considerable amount of moisture, 
so that the separation into the individual cells could hardly have 
been called forth by an insufficient amount. In the original cul- 
ture the spores were sowed in the center of the Petri dish, and 
after several weeks of growth only covered an area about 2™ in 
diameter. After ten weeks nearly the whole Petri dish (6™ in 
diameter) was filled with a luxuriant growth of protonemata, a 
large majority of which had grown from separate cells. 
The cultures in the light on agar-agar produced no buds 
although they were exposed to sufficient illumination for four 
months. The control culture on earth had produced an abund- 
ance of buds after nine weeks. The growth of the whole pro- 
tonema was not as vigorous as in the control experiment. Fig. 
4 shows where the original spore cell has started to form a bud 
by the insertion of an oblique cross wall; further than this, how- 
ever, no indication of bud formation was noted. The cultures 
in the dark produced protonemata of considerable size and vigor, 
but the vigor of growth was markedly below the same cultures 
in the light. The protonemata were perfectly free from chloro- 
phyll, and the considerable size attained shows that to a certain 
extent they are able to adapt themselves to a saprophytic mode 
of nourishment. 
In the light the main protonemal axes were directed parallel 
to the incident rays of light, and grew either in or on the sur- 
face of the culture medium. The secondary branches grew erect 
from the prostrate axes, and directed themselves towards the 
light at an angle of about 45°, thus exhibiting a marked positive © : 
heliotropism. Sachs% has already referred to the so-called 
dorsiventrality of Funaria protonema. In the dark the main 
axes were without any definite direction, while the secondary 
branches grew more or less vertical, but irregularly in all direc- 
tions. Whether this vertical growth of the secondary branches 
in the dark is due to negative geotropism, I am not able as yet 
3 Vorlesungen iiber Pflanzenphysiologie 640. 1882. 
