232 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Myuroclada (Brackytheciese). Caulis illecebrinus, ramis turgide 
julaceis, simplicibus, fasciculatis, interdum arcuatis, ramulosis ; folia 
dense imbricata, vernicosa, cocbleari-concava, rotunda v. ovata, acuminata, 
areolatione subrkomboidea, semi-costata ; capsula in pedicello unciali 
Igevi inclinata, ovato-cylindrica v. cernua ; operculo conico, longe ros- 
trato ; peristomium hypnoideum, magnum ; dentes interni valde biantes. 
Under the nam eStrucJcia, Dr. K. Muller* * * § separates from Hypnum the 
species argentatum, and forms it, together with three new species, into a 
genus with the following diagnosis ; — Folia e basi plus minus constricta, 
latiuscule ovata, in acumen longissimum cuspidata ; theca in pedunculo 
longissimo glabro erecta, ovalis, microstoma ; annulus latus ; peristomium 
simplex; dentes externi 16, breves, lineari-lanceolati, parce trabeculati; 
calyptra dimidiata, caulis plumosus. 
Structure of Buxbaumia.f — Prof. F. 0. Bower criticizes Goebel’s 
explanation of the peculiarities in the structure of Buxbaumia , and 
argues that they may be largely the result of reduction rather than an 
indication of the survival of an archaic structure. Prof. Bower further 
contests Goebel’s statement J that it can be experimentally proved that 
the sporophylls of leptosporangiate ferns are modified leaves. 
Relations of Nucleus to Spore-formation in Liverworts.§— Prof. 
J. B. Farmer reminds us that, as a general rule, during the formation of 
spore-tetrads from their mother-cells, the nucleus of the latter undergoes 
two successive bipartitions. Each of the resulting four nuclei ultimately 
becomes a centre for the aggregation of a portion of the original proto- 
plasm. The deviations he has observed are probably modifications of 
this method. 
After briefly describing what may be seen in Aneura multifida and 
A. pinguis, the author remarks that the most conclusive and striking 
results were obtained with Steetzia decipiens , which he collected in 
Ceylon. The nucleus is invested by a dense mass of protoplasm 
(archoplasm), and this, as in A. pinguis, forms a quadripolar achromatic 
spindle, while the nucleus is still in the resting condition. The ends 
of the spindle severally reach out to a point beyond the centre of each 
lobe. Though he calls the spindle achromatic, following the common 
usage, the author found that it stains deeply with hmmatoxylin, saffranin, 
or gentian-violet ; the chromatic portion of the nucleus forms a large 
mass in the centre, and becomes four-lobed, the lobes being united 
centrally till quite late. When they separate each breaks into two 
chromosomes of a rod-like shape, and they speedily arrange themselves 
in pairs; each pair furnishes the chromatic element to the daughter- 
nucleus. The cell walls rapidly meet in the centre, and their union is 
effected before the reconstruction of the daughter-nuclei. The spindle 
mass contracts up to the middle of each of the four cells, and invests the 
young nucleus in the same manner as was the case with the original 
body. 
* Rev. Bryol., xx. (1893) pp. 91-5. 
t Ann. Bot , vii. (1893) pp. 367-80. Cf. this Journal, 1893, p. 216. 
X Of. this Journal, 1888, p. 261. 
§ Proc. Roy. Soc. Lond., liv. (1893) pp. 478-80. 
