1898 } REGENERATION AS EXHIBITED BY MOSSES 197 
one portion of the stem as another. Defoliated stems generally 
produced one or two new plants as lateral branches. The origin 
of these was not definite, since they appeared now at the base, 
now at the apex, and at intervening points. Whole plants 
placed under the same condition as defoliated ones also pro- 
duced an abundance of protonemata direct from the leaf axil, 
the same as in defoliated stems. The production of new shoots 
was also as abundant in the whole plants as in the case of the 
defoliated stems. Hence, Leptobryum differs from the other 
species already described in that the protonema production is 
not called forth by defoliation. 
The form of branching of the protonemata of Leptobryum is 
worthy of note, since it very frequently differs from the ordinary 
mode. In the normal branching of protonemata each cell is 
able to form a branch. just behind the cross septum. In this 
case, however, two branches are formed opposite each other and 
immediately behind the septum (fig. 48). The plants which I 
used for experiments were grown in the greenhouse, and an 
examination of sterile plants showed that the production of pro- 
tonemata from the leaf axils was quite general. The side 
branches of these protonemata often gave rise to strings of con- 
idia-like cells, which broke away from the branch bearing them. 
The cells generally had assumed an oval form, were abundantly 
filled with chlorophyll bodies and quite often large oil drops, 
and possessed besides slightly thicker walls (figs. 43, 4). The 
striking similarity of this growth to conidia formation in fungi 
will at once be noted from the diagram. Some of these conidia- 
like cells were placed in conditions favorable for growth and 
after a lapse of about eight days germination or growth had 
occurred as shown in fig. 45. A great many of the leaf axils, 
instead of giving rise to protonemata or rhizoids, had produced 
dark brown, oval, multicellular brood-bodies borne upon a stalk 
several cells long ( figs. g6, 47). The rhizoids also gave rise to 
similar brood-bodies. The conditions for this conidia produc- 
tion cannot be stated. In the artificial cultures when kept 
moist, this manner of breaking up of the protonemal branches 
