Wikisource

Page:EB1911 - Volume 20.djvu/590: Difference between revisions

Browse history interactively
← Older edit
→‎Proofread: PALAEOBOTANY
→‎Validated: Sphenozamiles→Sphenozamites; add italics and add hyphen after cf. theodora.com/encyclopedia/p/palaeobotany.html; use Unicode italics for variables
Tag: Validated
 
Page statusPage status
-
Proofread
+
Validated
Header (noinclude):Header (noinclude):
Line 1: Line 1:
{{rh|{{x-larger|538}}|{{x-larger|PALAEOBOTANY}}|[PALAEOZOIC}}{{EB1911 fine print/s}}
{{rh|{{x-larger|538  }}|{{x-larger|PALAEOBOTANY}}|[PALAEOZOIC}}
{{EB1911 fine print/s}}
Page body (to be transcluded):Page body (to be transcluded):
Line 1: Line 1:
in reality very distinct. Both male and female inflorescences
in reality very distinct. Both male and female inflorescences
have frequently been found in connexion with leaf-bearing branches
have frequently been found in connexion with leaf-bearing branches
(see restoration, fig. 30). The inflorescence is usually a spike
(see restoration, fig. 30). The inflorescence is usually a spike
bearing lateral cones or catkins, arranged sometimes distichously,
bearing lateral cones or catkins, arranged sometimes distichously,
sometimes in a spiral order. The investigation of silicified
sometimes in a spiral order. The investigation of silicified
specimens has, in the hands of Renault, yielded striking results.
specimens has, in the hands of Renault, yielded striking results.
A longitudinal section of a male ''Cordaianthus'' (the name applied to
A longitudinal section of a male ''Cordaianthus'' (the name applied to
isolated fructifications) is shown in fig. 31, A, Plate. The organ
isolated fructifications) is shown in fig. 31, A, Plate. The organ
figured is one of the catkins (about a centimetre in length) which
figured is one of the catkins (about a centimetre in length) which
were borne laterally on the spike. Some of the stamens are inserted
were borne laterally on the spike. Some of the stamens are inserted
Line 12: Line 12:
are grouped about the apex of the axis. Each stamen consists
are grouped about the apex of the axis. Each stamen consists
of a long filament, bearing several erect, cylindrical pollen-sacs at
of a long filament, bearing several erect, cylindrical pollen-sacs at
its summit (cf. fig. 31, B, Plate). Some of the pollen-sacs had
its summit (cf. fig. 31, B, Plate). Some of the pollen-sacs had
dehisced, while others still retained their pollen. The stamens are
dehisced, while others still retained their pollen. The stamens are
probably best compared with those of ''Ginkgo'', but they have also
probably best compared with those of ''Ginkgo'', but they have also
Line 23: Line 23:
ovules, each accompanied by a few bracts, while in others the lateral
ovules, each accompanied by a few bracts, while in others the lateral
appendages are catkins, each containing from two to several ovules.
appendages are catkins, each containing from two to several ovules.
In the catkin shown in longitudinal section in fig. 32, A, it appears
In the catkin shown in longitudinal section in fig. 32, A, it appears
that each ovule was borne terminally, on an extremely short axillary
that each ovule was borne terminally, on an extremely short axillary
shoot, as in ''Taxus'' among recent Gymnosperms. The ovule consists
shoot, as in ''Taxus'' among recent Gymnosperms. The ovule consists
Line 30: Line 30:
or pollen-chamber, with a narrow canal leading into it, precisely
or pollen-chamber, with a narrow canal leading into it, precisely
as in the ovules of ''Stangeria'' or other Cycads at the present day
as in the ovules of ''Stangeria'' or other Cycads at the present day
(fig. 32, B). Within the pollen-chamber, and in the canal, pollen grains
(fig. 32, B). Within the pollen-chamber, and in the canal, pollen-grains
are found, agreeing with those in the anthers, but usually
are found, agreeing with those in the anthers, but usually
of larger size (fig. 32, C). It was in this case that Renault first
of larger size (fig. 32, C). It was in this case that Renault first
<!-- column 2 -->
<!-- column 2 -->
made the exceedingly interesting discovery that each pollen-grain
made the exceedingly interesting discovery that each pollen-grain
contains a group of cells, presumably representing an antheridium
contains a group of cells, presumably representing an antheridium
(fig. 32, C). Recent observations have completely confirmed
(fig. 32, C). Recent observations have completely confirmed
Renault's interpretation of the facts, on which some doubt had been
Renault’s interpretation of the facts, on which some doubt had been
cast. In the isolated seeds of Cordaitales and Pteridosperms,
cast. In the isolated seeds of Cordaitales and Pteridosperms,
pollen-grains are often found within the pollen-chamber, and the
pollen-grains are often found within the pollen-chamber, and the
Line 60: Line 60:
representatives from the latest Palaeozoic horizons.
representatives from the latest Palaeozoic horizons.


{|align="center" width="400"
{|{{Ts|ma|width:565px}}
|[[Image:EB1911 Palaeobotany - Cordaianthus.jpg|350px|center]]
|[[Image:EB1911 Palaeobotany - Cordaianthus.jpg|350px|center]]
|-
|-
|{{sm|(All after Renault.)}}
| {{sm|(All after Renault.)}}
|-
|-
|align="center"|{{sc|Fig.}} 32.—Cordaianthus.
|{{Ts|ac}}|{{sc|Fig.}} 32.—''Cordaianthus''.
|-
|-
|
|
A, ''C. Williamsoni.'' Part of longitudinal section of ♀ catkin; ''a'',
A, ''C. Williamsoni''. Part of longitudinal section of ♀ catkin; 𝑎,
axis, showing ''v'', bundles in tangential section; ''br'', bracts; ''d'', short
axis, showing 𝑣, bundles in tangential section; 𝑏𝑟, bracts; 𝑑, short
axillary shoot, bearing a bracteole and a terminal ovule; ''i'', integument;
axillary shoot, bearing a bracteole and a terminal ovule; 𝑖, integument;
''n'', nucellus of ovule; ''ov'', another ovule seen from the outside.
𝑛, nucellus of ovule; 𝑜𝑣, another ovule seen from the outside.
(× about 10.)
(✕ about 10.)
|-
|-
|
|
B, ''C. Grand' Euryi.'' Nucellus of an ovule; ''p.c.'', pollen-chamber;
B, ''C. Grand’ Euryi''. Nucellus of an ovule; 𝑝.𝑐., pollen-chamber;
''s'', canal leading to ''p.c.''; ''p'', pollen-grains in ''p.c.''; ''p′'', do. in canal.
𝑠, canal leading to 𝑝.𝑐.; 𝑝, pollen-grains in 𝑝.𝑐.; 𝑝′, do. in canal.
(× about 30.)
(✕ about 30.)
|-
|-
|
|
C, ''C. Grand' Euryi.'' Lower part of canal, enlarged; ''o'', cavity of
C, ''C. Grand’ Euryi''. Lower part of canal, enlarged; 𝑜, cavity of
canal, surrounded by a sheath of cells, dilated towards the bottom
canal, surrounded by a sheath of cells, dilated towards the bottom
of canal, in which a large pollen-grain is caught; ''ex'', exterior of pollen grain;
of canal, in which a large pollen-grain is caught; 𝑒𝑥, exterior of pollen grain;
''in'', internal group of prothallial or antheridial cells. (× 150.)
𝑖𝑛, internal group of prothallial or antheridial cells. (✕ 150.)
|-
|-
|
|
D, ''Cycadinocarpus augustodunensis''. Upper part of seed, in longitudinal
D, ''Cycadinocarpus augustodunensis''. Upper part of seed, in longitudinal
section; ''i'', integument; ''mi'', micropyle; ''n'', remains of
section; 𝑖, integument; 𝑚𝑖, micropyle; 𝑛, remains of
nucellus; ''p.c.'', pollen-chamber (containing pollen-grains), with its
nucellus; 𝑝.𝑐., pollen-chamber (containing pollen-grains), with its
canal extending up to the micropyle; ''pr'', part of prothallus;
canal extending up to the micropyle; 𝑝𝑟, part of prothallus;
''ar'', archegonia. All figures magnified.
𝑎𝑟, archegonia. All figures magnified.
|}
|}


Line 98: Line 98:
living plants. Their internal structure is sometimes admirably
living plants. Their internal structure is sometimes admirably
preserved, so that the endosperm with its archegonia is clearly
preserved, so that the endosperm with its archegonia is clearly
shown (fig. 32, D). It is a curious fact that in no case has an
shown (fig. 32, D). It is a curious fact that in no case has an
embryo been found in any of these seeds; probably fertilization
embryo been found in any of these seeds; probably fertilization
took place after they were shed, and was followed immediately by
took place after they were shed, and was followed immediately by
Line 104: Line 104:
belonged to Cordaitales, especially those seeds which had a flattened
belonged to Cordaitales, especially those seeds which had a flattened
form, such as ''Cardiocarpus'', ''Cycadinocarpus'', ''Samaropsis'', &c.
form, such as ''Cardiocarpus'', ''Cycadinocarpus'', ''Samaropsis'', &c.
Seeds of this kind have been found in connexion with the Cordaianthus
Seeds of this kind have been found in connexion with the ''Cordaianthus''
inflorescences; the winged seeds of ''Samaropsis'', borne on long
inflorescences; the winged seeds of ''Samaropsis'', borne on long
pedicels, are attributed by Grand' Eury to the genus ''Dorycordaites''.
pedicels, are attributed by Grand’ Eury to the genus ''Dorycordaites''.
Many other forms of seed, and especially those which show radial
Many other forms of seed, and especially those which show radial
symmetry, as for example ''Trigonocarpus'', ''Stephanospermum'' and
symmetry, as for example ''Trigonocarpus'', ''Stephanospermum'' and
Line 131: Line 131:
in form to the vegetative leaves, but smaller; sunk in their parenchyma
in form to the vegetative leaves, but smaller; sunk in their parenchyma
are numerous tubular loculi, containing large pollen-grains,
are numerous tubular loculi, containing large pollen-grains,
which are pluricellular like those of Cordaites; the female fructification
which are pluricellular like those of ''Cordaites''; the female fructification
had not yet been identified with certainty. The curious male
had not yet been identified with certainty. The curious male
sporophylls may perhaps be remotely comparable to those recently
sporophylls may perhaps be remotely comparable to those recently
discovered in Mesozoic Cycadophyta, of the group Bennettiteae.
discovered in Mesozoic Cycadophyta, of the group Bennettiteae.
Some leaves of Cycadean habit (''e.g.'' ''Pterophyllum'', ''Sphenozamiles'')
Some leaves of Cycadean habit (''e.g. Pterophyllum'', ''Sphenozamites'')
occur in the Coal Measures and Permian, and it is possible that
occur in the Coal Measures and Permian, and it is possible that
the obscure Coal Measure genus ''Noeggerathia'' may have Cycadean
the obscure Coal Measure genus ''Noeggerathia'' may have Cycadean
affinities. A fructification from the Permian of Autun, named
affinities. A fructification from the Permian of Autun, named
Cycadospadix milleryensis by Renault, appears to belong to this
''Cycadospadix milleryensis'' by Renault, appears to belong to this
family.
family.


Line 148: Line 148:
''Ullmannia'' and ''Pagiophyllum'', all of which resembled certain
''Ullmannia'' and ''Pagiophyllum'', all of which resembled certain
Araucarieae in habit. In the case of ''Walchia'' there is some evidence
Araucarieae in habit. In the case of ''Walchia'' there is some evidence
as to the fructifications, which in one species (''W. filiciformis'')
as to the fructifications, which in one species (''W. filiciformis'')
appear to be comparable to female Araucarian cones. There
appear to be comparable to female Araucarian cones. There
are also some anatomical points of agreement with that
are also some anatomical points of agreement with that
Retrieved from "https://en.wikisource.org/wiki/Page:EB1911_-_Volume_20.djvu/590"