. POCKETS OF CODON GG E££3 GAS GLAND 1223 PROJECTIONS OF CYST Text-fig. 2. Physalia physalis. Young left-handed specimen, number 5, x 8. Float-length 19 mm. To show origin of the crest as a fusion of crest-pockets. A, B from to windward, C, from above. PZ = protozooid at oral end, GG = gas-gland, S = septum, 1 = before fusion, 2 = after fusion. Part of the upper wall of the float is pushed out by the expanding muscular projections of the pneumatocyst, and the anterior wall of each pocket gradually fuses with the posterior wall of the adjacent pocket, forming a septum (Text-fig. 2), which grows
. POCKETS OF CODON GG E££3 GAS GLAND 1223 PROJECTIONS OF CYST Text-fig. 2. Physalia physalis. Young left-handed specimen, number 5, x 8. Float-length 19 mm. To show origin of the crest as a fusion of crest-pockets. A, B from to windward, C, from above. PZ = protozooid at oral end, GG = gas-gland, S = septum, 1 = before fusion, 2 = after fusion. Part of the upper wall of the float is pushed out by the expanding muscular projections of the pneumatocyst, and the anterior wall of each pocket gradually fuses with the posterior wall of the adjacent pocket, forming a septum (Text-fig. 2), which grows deeper as the fusion-process proceeds with age. The secondary, tertiary and subsequent septa develop in a similar way as the finger-like projections of the pneumatocyst divide and push out smaller pockets at a higher level (PI. X, fig. 7). The outer longitudinal muscles seem not to be involved in the fusion-process. A section of a septum shows a core of structureless lamella covered with gastrodermis. Leuckart (1851) stated that the septa were formed by the inner (gastrodermic) layer of circular muscles. To obtain accurate data on the relationship between float-length, saccus-capacity and area of gas-
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Keywords: ., bookcentury1900, booksubjectocean, booksubjectscientificexpediti
