1898 ] REGENERATION AS EXHIBITED BY MOSSES 195 
mata but only from the base and not from the cells lying along 
the cut margin. The power of regeneration is then located in 
the basal cells of the leaf the same as in Barbula muralis. The 
production is due to the separation of the leaves from the stem, 
since whole plants under exactly the same conditions as the 
detached leaves produced no protonemata, and since when the 
leaves were cut and still allowed to remain in connection with 
the stem no growth was called forth. 
Essentially the same results were obtained with leaves from 
a variety of this species, except that the protonemata originated 
exclusively from the cells of the base which occupied the posi- 
tion next the costa. 
The defoliated stems gave rise to new branches as axillary 
shoots, both from the main axes and from the side branches. 
These appeared without any apparent regularity with reference 
to base or apex of the stems, and also as well in the dark as in 
the light. In the dark the growth was more rapid, producing 
longer and slenderer shoots with very reduced leaves. Although 
the stems were cultivated for about two months no protonema 
production direct from the stems was observed. The production 
of rhizoids was not general, only here and there a few being 
produced. Whole plants brought into the same conditions as 
the defoliated stems, produced new plants in apparently as great 
abundance. The rhizoid production was about the same, so it 
was impossible to say that either rhizoid or shoot production was 
accelerated by defoliation. 
Q. LEPTOBRYUM PYRIFORME. 
The leaves of Leptobryum compare very favorably with 
those of Brachythecium rutabulum in the extent to which they 
produce protonemata, perhaps not more than one in ten of the 
leaves used showing the formation of a new growth. The first 
appearance of protonemata was noted after the leaves had been 
in culture for nearly three weeks. As in Bryum and Brachythe- 
cium, the first growth was semi-protonemal in character. With 
continued exposure to light and increase in length, it assumed 
