. Bonner zoologische Monographien. Zoology. 33 The \ entral coelom is bordered b\- naiTow epithelial cells, w hich ma\- occasional- !}â show high transcriptional acti\'it\- () or possess myoepithelial features (). The s\stem is contractile in these stages (Stach 1998). The mesodemi of the neurulae with nine segments is restricted to the dorsolateral pans of the animals (Plate 1: Stach 1994). Later the mesodemi grows out \'entral- 1\- (Plates 5. ~. S). This is seen in the neurulae whh ten and elexen segments. In these stages, the \-entral mesodermal cells sun-ound the archenteron.
. Bonner zoologische Monographien. Zoology. 33 The \ entral coelom is bordered b\- naiTow epithelial cells, w hich ma\- occasional- !}â show high transcriptional acti\'it\- () or possess myoepithelial features (). The s\stem is contractile in these stages (Stach 1998). The mesodemi of the neurulae with nine segments is restricted to the dorsolateral pans of the animals (Plate 1: Stach 1994). Later the mesodemi grows out \'entral- 1\- (Plates 5. ~. S). This is seen in the neurulae whh ten and elexen segments. In these stages, the \-entral mesodermal cells sun-ound the archenteron. The cells are narrow and ma\' be present in one or t^vo sheets, but ahvays make up a solid tis- sue. In the earliest lar\ al stages small intercellular spaces are present in the \'en- tral mesodemi (Plate 9). Hatschek's nephridium (Figs. 15-1": Plate 11. B & C) Hatschek's nephridium de\'elops ontogeneticall}' in the second mesodermal seg- ment of the left side (counted without the di\'erticulum of Hatschek). The neurula. : Transmission electron micrographs of Hatschek's nephridium of a lar\-al stage of Branchiostonia kmceolatum (llOh pf 18'C). A - C\-nopodocytes on the enlarged ecm where the rudiment of the aorta is fonned. B - Cross section through the posterior canal of Hatschek's nephridium. cc - canal cell, cci - central cilium. ci - cilium. ct - coelothel. cy - c\ nopodoc\-te. ecm - extracellular matrix, ep - epidennis. lao - anläge of the left anterior aona. ms - mesodemi of the first segment, my - m\-oc\ie. nc - notochord. nu - nucleus, rm - rod-like Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bonn, Zoologisches Forschungsinstitut und Museum Alexander Koenig
Size: 1799px × 1389px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectzoology
