296
Waters’ papers give the appearance of being mainly
taxonomic in character but in fact they frequently contain
valuable information on bryozoan anatomy and reproduction. For instance, anatomical fi gures from his works were
widely used in the monographs of Canu and Bassler ( 1920 ,
1929 ). Waters carried out thin-sectioning in order to use anatomical characters for the purposes of classifi cation. Using
sections, he counted tentacle numbers and described muscles, glands and gonads. In some instances, this information
can be found simply by examining his illustrations. For
instance, there is an ovary with eight oocytes depicted inside
a sectioned zooid of Menipea roborata (as Flabellaris )
(Waters 1896b [1898] ). In Cystisella saccata (as Porella ),
testes and an ovary are fi gured in obviously gonochoristic
zooids (Waters 1900 ), and a developing embryo is pictured
in the tentacle sheath of the ctenostomes Walkeria uva (as
Valkeria ) and Bowerbankia imbricata (Waters 1910 ). There
are brief remarks on reproductive characters in taxonomic
descriptions in other papers (Waters 1904a , 1906 , 1914 ,
1919 [1921] ). For instance, he wrote: “No doubt the nature,
size, shape and position of the ovaria will have to be used in
the classifi cation of Alcyonidiidae” (Waters 1904b , p. 86).
Additionally, an intertentacular organ was found in the
simultaneously hermaphrodite zooids of Alcyonidium antarcticum . Waters ( 1896a [1898] , 1913 ) was the fi rst to discover brooding in the external ovisacs of Aetea species (see
above). His study of the peristomial ovicells of Margaretta
chuakensis (as Tubucellaria ceroides var. chuakensis )
revealed that a large ovary is normally situated below a dwarf
polypide, although young ovaries may occur in different
places, being frequently associated with a funicular strand
near the point where it enters one of the lateral rosette-plates
(Waters 1907 ). Waters stated that the dwarf polypide is
formed not by polypide recycling, but by a modifi cation of
the original polypide, and he was in doubt as to whether it
could serve for larval release. At the same time, he asked if
the polypide could bring “spermatozoa … to the growing ova
of the ovarium” ( 1907 , p. 128). Waters’ schemes show macrolecithal eggs forming within an ovary of cylindrical epithelial cells in this species. In the ovicells of Thalamoporella
rozieri , he found up to three embryos of different ages all
surrounded by fertilization envelopes. He mentioned the
unusual structure of the ovary in this species, in which “ovarian cells are partly surrounded by a coarse cellular network”
(Waters 1909 , p. 141).
When studying internal brooding in a number of cheilostomes in the genera Adeona , Adeonella , Adeonellopsis ,
Laminopora, Beania and Watersipora (as Lepralia ), Waters
( 1912 ) discovered (but again, did not understand) extraembryonic nutrition. He wrote that embryos were surrounded
by a “thick-walled sac” [embryophore of the internal brood
sac] and occupied half or even almost all zooid cavity in
“adeonid” genera and Beania , but that the eggs found were
of small to moderate size. Briefl y describing the female
gonad in “adeonids”, he wrote that the ovary is positioned in
the distal part of the zooid, near the proximal part of the
brood sac. It contains two, occasionally, three small oocytes,
of which only one reaches a moderate size (in Adeona foliifera fascialis (as A . foliacea var. fascialis )). In this paper,
Waters proposed to divide all Bryozoa into two groups
according to ovarian structure, discussing the utility (“classifi catory assistance”) of this character. He defi ned (1)
“bicellular” ovaries “with only two, or perhaps three, small
ovarian cells [oocytes], neither of which grows to any large
size, but passes into the ovicell quite small”, and (2) “multicellular ovaria with many ovarian cells, one or more of which
often attain to a considerable size”, noting that “multicellular
forms may pass through a stage somewhat like the bicellular” ( 1912 , pp. 496–497). He considered Bugula (and obviously the “adeonids”) as an example of the “bicellular”
variant, and Scrupocellaria as an example of the “multicellular” one, which corresponds with my data on oocyte
number in matrotrophic and non-matrotrophic species (see
Chap. 1 ). Testes were said to “nearly fi ll” the zooid cavity
[obviously in male zooids] in Laminopora contorta (p. 498).
In a later paper Waters ( 1913 ) described and depicted the
hypertrophied epithelium of the brood sac in Adeonella platalea .
In Poricellaria ratoniensis (as Diplodidymia complicata )
the small egg begins its growth in the small brood sac, hanging
below the zooidal operculum. Both then enlarge to such an
extent that they fi ll most of the zooid cavity. Once again,
Waters did not understand that he had discovered placental
nutrition in both these cases, but he did realize it in the case
of Catenicella elegans (as Vittaticella ), writing that there are
“several fl eshy bands or tubes [funicular strands] by which …
material for growth is transferred to the ovicell”, containing
a large embryo in this species ( 1913 , p. 485).
In this paper the position of the gonads and the number of
eggs in the ovary were recorded in 16 cheilostome species.
For three other species he gave data about the position of the
embryo in the brood-chamber: for instance, embryos surrounded by a membrane were suggested to be brooded in
the “internal ovicell” [brood sac] in Steginoporella magnilabris (as Steganoporella ) ( 1913 , p. 500). A similar fi nding
was made by Marcus ( 1922 ), who recorded membranebounded embryos and ovary in Steginoporella haddoni (as
Steganoporella ). Waters ( 1913 ) further considered that the
size and position of the ovary and the size and the number of
eggs might be useful generic characters. He grouped
together the genera Canda , Caberea , Scrupocellaria ,
Bugulopsis and Menipea as having a large, distal ovary with
several eggs, one of which grew quite large before oviposition occurred. In contrast, Bugula and Bicellariella (as
Bicellaria ) had a small, proximal ovary with only two
(rarely 3–5) small eggs, one of which is transferred to the
ovicell. For this reason, Waters endorsed the segregation of
Appendices
Waters’ papers give the appearance of being mainly
taxonomic in character but in fact they frequently contain
valuable information on bryozoan anatomy and reproduction. For instance, anatomical fi gures from his works were
widely used in the monographs of Canu and Bassler ( 1920 ,
1929 ). Waters carried out thin-sectioning in order to use anatomical characters for the purposes of classifi cation. Using
sections, he counted tentacle numbers and described muscles, glands and gonads. In some instances, this information
can be found simply by examining his illustrations. For
instance, there is an ovary with eight oocytes depicted inside
a sectioned zooid of Menipea roborata (as Flabellaris )
(Waters 1896b [1898] ). In Cystisella saccata (as Porella ),
testes and an ovary are fi gured in obviously gonochoristic
zooids (Waters 1900 ), and a developing embryo is pictured
in the tentacle sheath of the ctenostomes Walkeria uva (as
Valkeria ) and Bowerbankia imbricata (Waters 1910 ). There
are brief remarks on reproductive characters in taxonomic
descriptions in other papers (Waters 1904a , 1906 , 1914 ,
1919 [1921] ). For instance, he wrote: “No doubt the nature,
size, shape and position of the ovaria will have to be used in
the classifi cation of Alcyonidiidae” (Waters 1904b , p. 86).
Additionally, an intertentacular organ was found in the
simultaneously hermaphrodite zooids of Alcyonidium antarcticum . Waters ( 1896a [1898] , 1913 ) was the fi rst to discover brooding in the external ovisacs of Aetea species (see
above). His study of the peristomial ovicells of Margaretta
chuakensis (as Tubucellaria ceroides var. chuakensis )
revealed that a large ovary is normally situated below a dwarf
polypide, although young ovaries may occur in different
places, being frequently associated with a funicular strand
near the point where it enters one of the lateral rosette-plates
(Waters 1907 ). Waters stated that the dwarf polypide is
formed not by polypide recycling, but by a modifi cation of
the original polypide, and he was in doubt as to whether it
could serve for larval release. At the same time, he asked if
the polypide could bring “spermatozoa … to the growing ova
of the ovarium” ( 1907 , p. 128). Waters’ schemes show macrolecithal eggs forming within an ovary of cylindrical epithelial cells in this species. In the ovicells of Thalamoporella
rozieri , he found up to three embryos of different ages all
surrounded by fertilization envelopes. He mentioned the
unusual structure of the ovary in this species, in which “ovarian cells are partly surrounded by a coarse cellular network”
(Waters 1909 , p. 141).
When studying internal brooding in a number of cheilostomes in the genera Adeona , Adeonella , Adeonellopsis ,
Laminopora, Beania and Watersipora (as Lepralia ), Waters
( 1912 ) discovered (but again, did not understand) extraembryonic nutrition. He wrote that embryos were surrounded
by a “thick-walled sac” [embryophore of the internal brood
sac] and occupied half or even almost all zooid cavity in
“adeonid” genera and Beania , but that the eggs found were
of small to moderate size. Briefl y describing the female
gonad in “adeonids”, he wrote that the ovary is positioned in
the distal part of the zooid, near the proximal part of the
brood sac. It contains two, occasionally, three small oocytes,
of which only one reaches a moderate size (in Adeona foliifera fascialis (as A . foliacea var. fascialis )). In this paper,
Waters proposed to divide all Bryozoa into two groups
according to ovarian structure, discussing the utility (“classifi catory assistance”) of this character. He defi ned (1)
“bicellular” ovaries “with only two, or perhaps three, small
ovarian cells [oocytes], neither of which grows to any large
size, but passes into the ovicell quite small”, and (2) “multicellular ovaria with many ovarian cells, one or more of which
often attain to a considerable size”, noting that “multicellular
forms may pass through a stage somewhat like the bicellular” ( 1912 , pp. 496–497). He considered Bugula (and obviously the “adeonids”) as an example of the “bicellular”
variant, and Scrupocellaria as an example of the “multicellular” one, which corresponds with my data on oocyte
number in matrotrophic and non-matrotrophic species (see
Chap. 1 ). Testes were said to “nearly fi ll” the zooid cavity
[obviously in male zooids] in Laminopora contorta (p. 498).
In a later paper Waters ( 1913 ) described and depicted the
hypertrophied epithelium of the brood sac in Adeonella platalea .
In Poricellaria ratoniensis (as Diplodidymia complicata )
the small egg begins its growth in the small brood sac, hanging
below the zooidal operculum. Both then enlarge to such an
extent that they fi ll most of the zooid cavity. Once again,
Waters did not understand that he had discovered placental
nutrition in both these cases, but he did realize it in the case
of Catenicella elegans (as Vittaticella ), writing that there are
“several fl eshy bands or tubes [funicular strands] by which …
material for growth is transferred to the ovicell”, containing
a large embryo in this species ( 1913 , p. 485).
In this paper the position of the gonads and the number of
eggs in the ovary were recorded in 16 cheilostome species.
For three other species he gave data about the position of the
embryo in the brood-chamber: for instance, embryos surrounded by a membrane were suggested to be brooded in
the “internal ovicell” [brood sac] in Steginoporella magnilabris (as Steganoporella ) ( 1913 , p. 500). A similar fi nding
was made by Marcus ( 1922 ), who recorded membranebounded embryos and ovary in Steginoporella haddoni (as
Steganoporella ). Waters ( 1913 ) further considered that the
size and position of the ovary and the size and the number of
eggs might be useful generic characters. He grouped
together the genera Canda , Caberea , Scrupocellaria ,
Bugulopsis and Menipea as having a large, distal ovary with
several eggs, one of which grew quite large before oviposition occurred. In contrast, Bugula and Bicellariella (as
Bicellaria ) had a small, proximal ovary with only two
(rarely 3–5) small eggs, one of which is transferred to the
ovicell. For this reason, Waters endorsed the segregation of
Appendices