Makers of British Botany; a collection of biographies by living botanists
History
Makers of British Botany; a collection of biographies by living botanists
Botanists -- Great Britain -- Biography; Botany -- Great Britain -- History
One of the Liverworts Griffith described may be taken as an
illustration to this part of our subject on account of the interest
of its re-discovery and re-description in 1910 by Goebel. This is
a plant collected in Assam and named _Monosolenium tenerum_. This
Marchantiaceous plant is described as having no air-chamber layer,
as bearing sessile, dorsal, antheridial receptacles, and terminal,
shortly stalked archegoniophores with one ventral groove in the stalk.
A single archegonium--later capsule--is found in each of the half-dozen
involucres. Spores and irregular bodies were found in the capsule.
Recently Goebel had two tea-plants sent home from Canton. They died,
but he kept the soil moist on the chance of germinating seeds. Among a
number of other plants there turned up a new Liverwort. On examination
this proved to be Griffith's _Monosolenium_--all types of which had
been lost--a most interesting form related to the Corsiniaceae.
In the Mosses and the Liverworts generally Griffith was clear on the
development of the capsule or fruit following on the impregnation of an
archegonium. But in _Anthoceros_, while he recognised the antheridia he
was not clear as to the sunken archegonia, and regarded the capsules
as arising by impregnation of unrecognisable spots on the young frond
or thallus. He observed however the indication of the canal of the
archegonial neck above the young capsule.
Analogy with _Anthoceros_ confirmed him in his views on the
reproduction of ferns. Here he spent much labour in considering the
view, originally due to Hedwig, that the ramenta were male organs by
the effect of which the sporangia developed. Griffith saw that if this
was so, since the sporangia are initiated very early, the only time to
search for the male organs was in the very young stage of the leaf. On
examining such young leaves he found the terminal cells of the young
ramenta very prominent and formed the working hypothesis that they were
the male organs. But he stated this cautiously and was well aware how
imperfect his means of observation were.
The whole line of work brings vividly before us how cryptogamic the
Cryptogams were at this period.
Without attempting to survey Griffith's views on the various groups
of Vascular Cryptogams, a word must be said of those on _Salvinia_
and _Azolla_, on which he published a long paper in addition to the
other descriptions and figures in the _Notulae_. His observations bear
on the development of the sorus and sporangium, but he dismissed the
microsporangia as abortive or imperfectly developed structures. (I may
note in passing that the study of their development led him to regard
the microsporangia of _Isoetes_ in the same way.) He dwelt on the
similarity of the sporangium and indusium of _Azolla_ to a gymnospermus
ovule, and regarded the filaments of _Anabena_ seen penetrating within
the indusium as probably the fertilising bodies in this naked-seeded
cryptogam.
Public-domain text, read in full here on John Shaqi.
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