1898 | REGENERATION AS EXHIBITED BY MOSSES 207 
inated only from the axillary cells, in other cases from the 
various surface cells of the internode. The axillary shoots in 
one case showed a tendency to marked apical origin (Mnium). 
In the other cases the distribution was quite general. 
10. The buds originated from Mnium leaves and Fissidens 
stems without the intervention of a protonema. When of pro- 
tonemal origin, they were either modifications of lateral pro- 
tonemal or rhizoidal branches, or direct modifications of the 
main axes. The tendency of protonemata to produce rhizoids 
was not as great as the tendency of rhizoids to produce pro- 
tonemata. 
i1. The upper temperature limit for regeneration from the 
leaves investigated varied from 24 to 32° C. Protonemata were 
grown in I and 2 per cent. solutions of KNO,. Drying for a 
considerable length of time did not alter the power of the leaf 
to produce protonemata. 
The investigations here recorded were carried out during 
the years 1896-7 in the laboratory of the Botanical Insti- 
tute at Leipzig, under the direction of Herr Geh. Professor Dr. 
Pfeffer. I wish here to express my thanks to him for aid and 
many valuable suggestions. 
PARSONS COLLEGE, 
Fairfield, Ia. 
EXPLANATION OF PLATES XIX—XxX. 
PLATE XIX. 
Mnium rostratum. 
Fig. 1. Diagram of a leaf to show origin of rhizoids and buds. X 12. 
Fig. 2. Cross section of a portion of a leaf showing the origin of a bud 
from a leaf cell, together with the previously produced rhizoid. X 130. 
Fic, 3. Cross hehe of a portion of a leaf showing a bud at a more 
advanced stage. 3 
G. 4. ae. of a leaf with rhizoids and a bud produced as a [Matera 
aie of a rhizoid. x 53 
