1910] CURRENT LITERATURE 475 
from that found in Botrychium; while in Helminthostachys the fertile spike is 
interpreted as representing a single pinna. This would dispose of the sporangio- 
phore nature of the spike, and revert to ROEPER’s view (in 1826) that it represents 
two fused basal pinnae. 
The general conclusion is that the Ophioglossaceae are related to the ferns, 
and “‘have sprung from near the level of the Osmundaceae.”—J. M. C 
The strobilus of Selaginella.—Miss GERTRUDE MITCHELL? has recorded 
some general studies of the strobilus of Selaginella, which fill up certain gaps in 
our knowledge, and “‘confirm or controvert statements” of other investigators. 
In some species the axis was observed to renew its ordinary vegetative char- 
acter beyond the strobilus: in one case abortive sporangia were produced in the 
axils of the foliage leaves just beyond the tip of the strobilus; in another species 
a second strobilus was produced upon such an axis, the two strobili being separated 
by a sterile region; and in still another case a branched strobilus was noted. The 
distribution of sporangia is variable; and species are enumerated under the follow- 
ing heads; one large basal megasporangium, several basal megasporangia suc- 
ceeded by microsporangia, strobili wholly megasporangiate or microsporangiate, 
and an indiscriminate arrangement. The species are also enumerated that 
mature one, two, or three megaspores, instead of the more usual four, and also 
two rare cases in which there are twelve (S. Vogelii) and eight (S. involvens) 
megaspores. Considerable attention is given to the sporangium wall and its 
mechanism for cea involving what are spoken of as “its wonderful adapta- 
tions for cross-fertilization. e paper closes with a igi consideration of the 
vascular anatomy of “ strobilus and the ligule-—J. M 
' The stele of Osmunda.—The vascular anatomy of this genus has given rise 
to much discussion and to divergent opinions as to its phylogenetic significance. 
FAUvuLL3 has now investigated abundant material of the sporelings of O. cinna- 
momea in all stages, and has reached the following results and conclusions: The 
cortical cells at the base of the sporeling are inhabited by a fungus. While there 
is considerable variation in the development of different individuals, in no case is 
the transition from protostele to siphonostele effected by a simple expansion, as 
has been claimed for Osmundaceae. There are bays or gaps in the xylem near 
the nodes, which may result in inclosing a ‘‘stelar” pith. Rarely and only in 
adult stems does the internal endodermis and ‘‘extrastelar”’ pith connect with the 
external endodermis and cortex through leaf gaps. Internal phloem has been 
found in unbranched adult plants, and this fact, together with the absence of 
branching in the sporeling, is thought to indicate that internal phloem and 
3? MITCHELL, GERTRUDE, Contributions towards a knowledge of ‘the anatomy 
of the sip ics Spr. Part V. The strobilus. Annals of Botany 24:19-34. 
pls. nie : 
NER, J. H., The stele of Osmunda cinnamomea. Trans. Canadian Inst. 
8:515-534. pls. 4-6. 1909 
