. Bulletin. Science; Natural history; Natural history. 7976 POSTANAL SAC OF THE GRAY WHALE i; :^V. 25cm. Figure 3. Photograph of two postanal sacs from fe- male specimens revealing the smooth inner wall and the coarse exterior blubber fibers. The arrows point to the two pits in the larger sac. been reported in two gray whales by Zimushko (1970). The pits or bhnd ducts noted in the sac have also been reported by Zimushko, as well. The sacs are usually turgid with fluid which varies in viscosity and opaqueness. The fluid may be nearly clear and watery, transluscent and murky, or a cheesy paste o
. Bulletin. Science; Natural history; Natural history. 7976 POSTANAL SAC OF THE GRAY WHALE i; :^V. 25cm. Figure 3. Photograph of two postanal sacs from fe- male specimens revealing the smooth inner wall and the coarse exterior blubber fibers. The arrows point to the two pits in the larger sac. been reported in two gray whales by Zimushko (1970). The pits or bhnd ducts noted in the sac have also been reported by Zimushko, as well. The sacs are usually turgid with fluid which varies in viscosity and opaqueness. The fluid may be nearly clear and watery, transluscent and murky, or a cheesy paste of whitish granules. Histological sections of the wall of the sac provide little clue of the nature of the sac. but the smooth lining suggests the possibility of a gland. CHEMICAL ANALYSIS The fluid of one sac (Table 1) was drawn out by puncturing the sac with an 18 au needle and aspirating with a 50 ml syringe. The fluid was frozen prior to chemical examination and was not exposed to any chemical fixatives. This fluid con- tained some precipitated materials which were removed by low speed centrifugation ( 1500 X g) and both the precipitate and the clarified super- natant were examined. The precipitate was examined in a Zeiss polariz- ing microscope and foimd to contain a gelatinous mass in which was embedded many spicule-shapcd crystals. They were not found in the supernatant. The addition of three volumes of saline or one volume of 1 N KOH was found to solubilize the gelatinous mass and leave the crystals intact. Figure 4. Histological cross section of the smooth inner wall of a sac illustrating an ordered striated structure. (Formalin fixed; embedded in Epon; methylene blue stain, X 100). whereas the addition of 95% methyl alcohol dis- solved the crystals and left the gelatinous mass intact. The addition of strong organic solvents (hexane. benzene) did not solubilize either the gel or the crystals. The failure of most organic solvents to either solubilize or extract substance
Size: 1557px × 1605px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectnaturalhistory, booksubjectscience
