. u2 mm Text-fig. 15. Physalia physalis. Cormidium 5 (oral zone) of a young specimen number 11, less group 1, to show the three parts, A, B, C, of an 'Urgruppe'. Note the endodermal villi. GZ of = gonozooid mentioned on p. 347. XII. beautiful young specimens, measuring 2-9 and 8 cm. in float-length, show clearly that at this stage there are at least eight lateral groups in cormidium I. They decrease in size according to youth, so that the one at the aboral end is a very small bud (PL XIV, fig. 3). Each group consists of a gastrozooid, a gonodendron and a tentacle. They look as if they mi
. u2 mm Text-fig. 15. Physalia physalis. Cormidium 5 (oral zone) of a young specimen number 11, less group 1, to show the three parts, A, B, C, of an 'Urgruppe'. Note the endodermal villi. GZ of = gonozooid mentioned on p. 347. XII. beautiful young specimens, measuring 2-9 and 8 cm. in float-length, show clearly that at this stage there are at least eight lateral groups in cormidium I. They decrease in size according to youth, so that the one at the aboral end is a very small bud (PL XIV, fig. 3). Each group consists of a gastrozooid, a gonodendron and a tentacle. They look as if they might be, and indeed at one time I thought they were, beginnings of new cormidia, but in each of the other cormidia of the main zone there is a counterpart of this series of lateral groups. As previously stated, there is evidence that the latest (youngest) cormidia to appear do so at the oral end of the budding-zone, whereas in the lateral groups the pattern of development is reversed, the youngest groups appearing at the aboral end of each cormidium. When fully developed, there may be from ten to twelve fan-shaped lateral groups (PL XV, fig. 4) in each main zone cormidium. They bud successively (PL XVII, fig. 4) each from the base of its predecessor and as growth proceeds they curl round (PL XV, fig. 6) so that the last small lateral of one cormidium can be seen lying to the oral side of the first and largest tentacle of the cormidium that lies at its aboral end. (4) Secondary basal branches. These tend to occur wherever there is room for further growth and expansion, that is, on the leeward side of the float, at the aboral ends of the cormidia, and, in the case
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Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
