464 
SISTER M. ELLEN 
4. . Spore formation and karyokinesis in Hepaticae. Annals of Botany 9: 363, 364. 
1895. 
EXPLANATION OF PLATES 
All figures were made with the aid of a camera lucida and drawn at table level. Leitz 
objective no. 6 and ocular no. 4 were used in making figures 1-9; objective no. 3 and ocular 
no. 4 were used in drawing figures 10-17. With a tube length of 170 mm., a magnification 
of about 660 was obtained in figures 1-9 and a magnification of 140 in figures 10-17. Foi" 
figures 18-28 a Bausch & Lomb 16 mm. objective and 12.5 mm, ocular gave a magnification 
of 200. These magnifications were reduced by one-third in reproduction. 
The following abbreviations are used: r, rhizoid; h, bud; s, sporeling; y t, young 
thallus; 5 c, secondary rhizoid. 
Plate XXXIV 
Fig. I. A spore mother cell. 
Fig. 2. Spore tetrad within the mother cell wall. 
Fig. 3, Spore just before its first division. 
Fig, 4. Two cells formed by the division of a spore and remaining surrounded by the 
spore wall. 
Fig. 5, Four cells formed within the spore wall. 
Fig, 6, Median longitudinal section of a sporeling showing five cells. Probably as 
many as eight cells are present. 
Fig. 7, Same as figure 6, after the thickening of the walls and the deposition of starch. 
Fig, 8, Condition of sporeling during the first series of spring divisions. 
Fig, 9, Median longitudinal section of a sporeling ready for dispersal. 
Fig. 10, First stage in external development, Sporeling twelve hours after being 
sown on rain water. 
Fig, II. Sporeling about twenty-four hours after being sown on rain water. 
Fig. 12, Later stage showing the development of a bud {h) which is to grow into a 
thallus. 
Fig. 13, Gametophytes about six days old showing secondary rhizoids. 
Plate XXXV 
Figs, 14, 15, Gametophytes developed in strong light. 
Figs, 16, 17, Sporeling which had suffered desiccation before being sown. No 
rhizoids have developed. 
Figs, 18, 19, Developing sporelings which were removed from the capsule before there 
was any advance toward spore dispersal. 
Figs, 20, 21, Later stages in the development of gametophytes treated like those 
shown in figures 18 and 19. 
Figs, 22-25, Stages in the external development of sporelings from the same collec- 
tion as those shown in figures 18 to 21, but which were not sown until after there was some 
elongation of the stalks of the carpocephala and of the setae of the sporophytes. 
Figs. 26-28. Stages in the external development of sporelings subjected to indoor 
conditions beginning March 7, and after which they were dispersed naturally. 
