Igo BOTANICAL GAZETTE [SEPTEMBER 
The protonemata originated only from the basal cells of the 
leaf, generally either from the very end cells or from those next 
the margin. The cells of the basal portion are much longer 
than those occupying the apical portion, and the question now 
presented itself as to whether the small cells of the apical half 
of the leaf were capable of growing out into protonemata. In 
order to determine this the basal portions were cut away from a 
series of leaves, and both apical and basal portions retained in 
culture. The result was that no protonemata were produced 
from the apical portions of the leaves, while the basal portions 
only produced protonemata from the cells of the proximal end. 
The protonemal growth was generally from cells occupying the 
periphery, but occasionally one originated from a cell a little 
removed from the margin. These experiments then show the 
power of regeneration to be confined to the larger cells of the 
leaf base. 
In the material which was accessible to me, most of the stems 
were bearing young sporophytes and had produced in their nor- 
mal growth an abundance of rhizoids. The defoliated stems 
when placed in culture did not give rise to any new shoots and 
no appreciable production of rhizoids was to be noted. 
6. ATRICHUM UNDULATUM. 
So far as my knowledge goes, no moss leaves with a struc- 
ture similar to that of Atrichum leaves have been known to give 
rise to protonemata.”” Hence the successful growth of proto- 
nemata from these leaves is of the more interest, Four cultures 
of leaves were made: a series of leaves with the dorsal surface 
uppermost, and another series with the ventral surface upper- 
most, both to be placed in the light; two similar series were 
placed in the dark chamber. At the end of a month the first 
signs of protonemata were observed and in the course of a week 
they had grown to a considerable length. An examination of all 
the cultures showed that the protonemata in every case origi- 
*7 Since this was written an article has appeared by Correns (Ber. deutsch. bot. 
se 16:22-27. 1898) describing the production of protonemata from Polytrichum 
eaves. 
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