304 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
mother-cell. In the following process of the separation of the daughter- 
chromosomes, two types may be distinguished, according as the separa- 
tion begins in the middle or at the ends, producing thus either double 
rods or annular chromosomes. After the separation is complete, the 
daughter-chromosomes collect at the poles, and there fuse into a single 
nuclear thread. This thread then splits longitudinally and divides 
transversely, as in the first division. No centrosomes could be detected, 
and no multipolar spindle-primordia. 
Archangiopteris, a New Genus of Filices.* — Herr H. Christ and 
Dr. K. Giesenhagen describe under this name a fern which they make 
the type of a new genus of Marattiaceae from S.W. China, somewhat 
intermediate between Angiopteris and Danaea, and possibly an ancestral 
form of the former genus. It differs from Angiopteris in the sori 
being linear, not oval, and median, not subterminal ; in the larger 
indusium ; in the sporanges being much more numerous ; the frond 
much smaller, only simply pinnate, and with no recurrent uervules ; 
from Danaea in the exarticulate stipe and rachis ; in the sporanges 
not being coalescent into a synange ; and in the presence of an 
indusium. 
Hymenophyllum with Bulbils.f — Under the name Hymenophyllum 
Ulei sp. n., Herr H. Christ and Dr. K. Giesenhagen describe a fern 
from Brazil, nearly related to H. ciliatum , but distinguished by the 
presence on the rhizome of bulbils, which are composed, in their upper 
portion, of tufts of hairs, and apparently serve as liydathodes for the 
temporary storing up of water in the form of rain or dew. 
Air in the Ripe Annulus-cells of Fern-Sporanges. | — Herr J. 
Schrodt answers in the affirmative the question whether the mature 
cells of the annulus of the sporange of ferns contain air. But whether 
this air has penetrated through the membrane when moist or when dry 
is not certain. Some observations made by the author would seem to 
indicate that the dry membrane is easily permeable for air. 
Muscinese. 
Direction of Growth of Mosses.§ — Herr B. Jonsson describes in 
detail the effect of external agencies, especially gravity, on the growth 
of mosses, which arrange themselves, on this point, in various groups. 
In one group, of which Homalothecium sericeum may be taken as the 
type, there are two kinds of vegetative shoot, the main and the lateral 
shoots. The former are adpressed to the substratum, and spread out in 
all directions, branching, in their lower portion, into stems with dorsi- 
ventral lateral organs. The leaves on the main shoots are generally 
closely adpressed to the stem, and have comparatively long apiculi. The 
lateral shoots are apparently arranged in pairs, and are at first adpressed 
to the substratum ; in later stages they grow free from it, and form two 
parallel rows. 
* Flora, lxxxvi. (1899) pp. 72-8 (5 figs.). f Tom. cit., pp. 79-85 (2 figs.). 
X Ber. Deutsch. Bot. Ges., xvi. (1898) pp. 322-30. 
§ Lunds Univ. Arsskr., xxxiv. (1898) 16 pp. See Bot. Centralbl., Beih., viii. 
(1899) p. 271. 
