bla ck, this is a felted web o f minute branched filaments o f protonema,
from which young plants bud off as in other m osse s; these are at
first globose and extremely minute. T h e almost invisible lea ves are
rather to be looked upon as perichætial b ra c ts , and are peculiar in
the flagelliform prolongations o f the marginal cells, which give them
a la ce rated appearance, and long before the c a lyp tra is ca st off they
become brown and dead. T h e reason o f this is explained by Z u k a l
thus ;— “ T h e ir a c tiv ity probably consists in the transmission of
moisture, and along with th e adventitious radic les th ey first form
a protection to the young archegonium, and then in the a c t o f
impregnation serve as a sponge, to take up fluid swarming with
antherozoids, and convey them to th e wa itin g a rchegonia, this
function ended, th ey wither and die.”
T a k in g a single plant, we observe at the base a bulb-like swelling
covered with a c lose felt o f proembryo filaments and minute leaves,
this by v e r tica l section we find is a cup-like sheath, embracing the
base o f the seta, th e ou te r ce lls o f which are large, quadrate, with
th ick w a lls and color less con tents, and b ecome the cu tic le o f th e seta,
the cells internal to this la ye r being long and thin walled, constitute
the bundle o f va s cu la r ce lls forming the centre o f the seta, while the
cup-like sheath is all we find to represent the parenchyma o f the
stem. In th e free seta the first two elements are more fully developed,
th e outer cu ticu la r ce lls being still further thicken ed into warts.
W h e r e the se ta joins th e capsule an elegant ne ck is formed, through
the centre o f which the vascu la r bundle is continued as the pedicel
o f the spore sa c, and then enlarges into the columella and passes
on to the apex o f the operculum. Around th e columella is the spore
sa c composed o f three cell-layers, th e c a v ity between it and the
capsu lar wall being tra versed b y numerous jo in ted confervoid filaments.
A transverse section through the lid, before matu rity , shows us a
c irc le o f la rge trian gular c e lls, the two la teral sides being equal, and
th e shorter base turned a ltern a te ly inward and outward, thus forming
a w a v y z ig z a g round the cen tral bundle o f v a s cu la r cells. In course
o f growth the short bases b ecome entirely resorbed, while th e lateral
sides o f the triangles grow to g e th er and become thicken ed into a
membrane, and th eir outward angles further strengthened by a stout
ridge o f ce llu lo se . It thus forms an enduring, rigid, tubular, tent-like
endostome, the function o f which is thus remarked on by Z u k a l :—
“ In many mosses the peristome only serves to prevent the spores
passing out o f the capsule in unfavorable w e a th e r ; i f th e spores
require warm, dry air as a n ecessary condition for germination, then
the peristome is so adapted th a t in w et, rainy weather it completely
closes the mouth, and on the contrary, i f moisture be the condition
needed, then in dry weather the peristome c loses the mouth o f the
capsule. T h e spores o f many mosses are first set free by the falling
in pieces o f th e capsule by decay, and until this occurs th ey must be
ripening ; in the cleistoca rpous mosses this is p rovided for b y the
absence o f a lid, and in the Poly tr icha ceæ by the d iscoid ally expanded
summit of the columella closing the mouth. In Buxbmitnia the lid
remains long a tta ch ed to the mouth, while it is firmly joined to the
columella by the vascula r bundle running through it, and only becomes
loosened by the rottin g o f the fruit ; the endostome also forms a high,
firm, conical membrane, with a small aperture at the apex, formed by
the falling awa y of the vascu la r bundle ; through th is narrow opening,
however, the spores cannot e scape, even i f the e re c t position o f the
fruit would allow it, and thus th ey are forced to remain in the capsule.
In time, the upper h alf o f the capsule separates a t th e la teral seam,
like a bivalve fruit, as it was described by old authors,— and thus a
free exit is made for the spo res.”
I follow C. Müller, Z u k al, and L ind b e rg in exc luding Webera E h r h .
(Diphyscnim M o h r .) from this family, for the tw o genera have nothing
in common but th e external form o f th e capsule, while the highly
developed seta, absence o f stem and degraded lea ves o f Buxbauima
are to ta lly opposed to the absence o f a p ed ice l, distinct stem, and
highly-developed leaves seen in Webera.
Besides the European species o f Buxbauima, the only others
recorded are B . Javanica C . M u e l l . and B . Tasinanica M i t t ., the
former very close to B . aphylla, the la tte r eq ua lly near to B . indusiata,
and probably not specifically distinct from them.
B y the depressed asymmetric capsule, so unusual in mosses, we
have some indications o f affinity with the exo tic genus Dawsoma,
and a further snpport to the position o f the family among the
Polytrichoideæ, though it must be admitted th a t the c ilia o f the
peristome o f Buxbaumia do present a few transverse a rticulations.
B U X B A U M I A . H a l l e r .
(Enum. Stirp. Helv. i, p. lo (1742).)
Plants very small, s ca ttered. Le a v e s extremely minute, broadly
ovate or oblong, coa rsely serrated, la xly areolate with oblongo-
hexagonal echlorophyllose cells, or palmato-laciniate, the laciniæ and
basal cells becoming altered by age into long filaments, and finally
into dense radicular tomentum. Inflorescence dioicous. Male plants
very minute, few-leaved, the b ra c ts not la ciniate, antheridia one or
two, subglobose, with few paraphyses. F ema le plants presenting
10-12 perichætial bra cts which after impregnation develop cilia.
Ca lyp tra very small conico-cylindr ic, generally c le ft at the side ;
capsule on a thick verrucose seta, with a short, erect neck, oblique,
ventricose, ovate, depressed above, with a conico-cylindr ic operculum.