upon a table in the middle of the laboratory. Two similar 

 preparations, were made and enclosed in a dark Chamber. 



After an interval of a week the first appearance of 

 rhizoids from the leaves was noted. An examination of the 

 specimens grown in the light showed that the rhizoids 

 proceeded almost exclusively from the contact surface, and 

 in gener al from the periphery of the leaf, although they 

 were not entirely absent from the middle and costal region. 

 An examination of the cultures in the dark showed nearly 

 the same manner of growth except that a considerably larger 

 number of rhizoids originated from the side upper most, the 

 Proportion being about 1 to 10. The rhizoids from the very 

 first, in both light and dark were devoid of Chlorophyll and 

 the cell-walls were distinctly brown. As growth proceeded, 

 those in the light developed an abundance of Chlorophyll 

 bodies and showed in nearly every case oblique cross-walls. 

 In the course of two weeks the rhizoids in the light had 

 branched considerably, while in the cultures in the dark they 

 rarely branched, and the cells were more elongated. At the 

 end of three weeks, the first appearance of buds was noted ; 

 and in cultures in brighter light in the window after a 

 lapse of two weeks. The buds originated exclusively from 

 the illuminated side and directly from a leaf cell without 

 the Intervention of any protonema. The buds generally 

 made their appearance near the periphery of the leaf and 

 the cell from which the bud originated had previously given 

 rise to a rhizoid from the contact side. This is shown in 

 cross sections of the leaf in Fig. 2 and 3. The mother cell 

 of the bud first produces a protuberance which becomes 

 divided very soon by an oblique wall, and the insertion of 

 the successive walls then follows in rapid order. Buds may 

 occasionally originate as side branches of the rhizoids from 

 either surface, although this is rare in the normal develop- 

 ment. At the end of six weeks, the specimens in the dark 

 showed no sign of buds, and the long unbranched rhizoids' 

 had attained a length of about one centimeter. The peculiar 

 method of regeneration shown in these experimentes is 



