F. Cavers. 
348 
gated ( N. Breutelii) by saying that “ the embryogeny conforms to the 
usual type for the Anthocerotaceae, but that the endothecium, instead 
of being devoted to the formation of a sterile columella, forms sporo- 
genous tissue for the greater part of the intercalary growth of the 
sporogonium. In a considerable proportion of cases, however, it 
produces sterile tissue towards the close of development.” His 
observations show that the endothecium must be regarded as 
potentially sporogenous, a fact which, according to this writer, 
“increases the justification for considering the central group of 
cells, which in all other Anthocerotaceae is wholly devoted to the 
formation of a sterile columella, as the original sporogenous tissue 
and the amphithecial archesporium is of secondary origin. The 
duty of producing spores would seem to have been transferred from 
the central to a more superficial set of cells.” Lang inclines to the 
view that the species of Notothylas are reduced forms, since “ the 
appearance of the archesporial layer derived from the amphi- 
thecium, even when the central cells are fertile, suggests an origin 
from forms with a sterile columella.” 
Among some specimens from the herbarium of Mr. W. H. 
Pearson, the writer found a species of Anthoceros (A. Hallii, Aust.) 
which differs considerably from the rest of this genus and approaches 
closely to Notothylas. The sporogonium of Notothylas is very 
small and when ripe projects but slightly beyond the “calyptra”or 
sheath; its epidermis has no stomata; there is practically no 
assimilating tissue; and the inner layers of the capsule-wall soon 
become disorganised (probably serving to nourish the developing 
spores). In Anthoceros Hallii the capsule (4 to 7 mm. long) projects 
beyond the sheath for less than one-third of its length. The pro¬ 
jecting apical portion bears a small number of remarkably large 
guard-cells; each cell of the capsule-wall contains two large 
chloroplasts ; the columella does not extend into the projecting tip 
of the sporogonium ; and the sterile cells have the stumpy flattened 
form characteristic of Notothylas, and bear irregular fibrous 
thickenings. Anthoceros Hallii appears to form an almost perfect 
connecting-link, in such characters as can be made out from 
nerbarium material, between the small-capsuled species of Antho¬ 
ceros on one hand and the forms included under the genus name 
Notothylas on the other. 
It has long been known that certain species hitherto included 
in the genus Anthoceros resemble Dendroceros in having the sterile 
cells developed as elaters with spiral bands, and in the absence of 
