. Fourteen weeks in zoology. Zoology. 86 SUBKINGDOM VEETEBBATA. Fig. ISS. The veins being destitute of valves, this huge animal bleeds to death from the single thrust of a lance, and in its last struggles, if the lungs are pierced, blood is forced out with the breath. The whale has a reserve system of blood-vessels. As fast as the venous blood returns and flows into a waste reservoir, a portion of the extra arterial blood passes into the circula- tion, and thus it can remain under water for an hour. Being an air-breathing ani- mal, it must come quickly to the sur- face; hence its tail* is flat
. Fourteen weeks in zoology. Zoology. 86 SUBKINGDOM VEETEBBATA. Fig. ISS. The veins being destitute of valves, this huge animal bleeds to death from the single thrust of a lance, and in its last struggles, if the lungs are pierced, blood is forced out with the breath. The whale has a reserve system of blood-vessels. As fast as the venous blood returns and flows into a waste reservoir, a portion of the extra arterial blood passes into the circula- tion, and thus it can remain under water for an hour. Being an air-breathing ani- mal, it must come quickly to the sur- face; hence its tail* is flattened horizon- tally instead of verti- cally, that a rapid stroke may throw up the head. Its skin. Salcena mysticUus, Eight Whale. consists of interlaced fibres, among which the fat is diffused to the depth, in some instances, of two feet,f forming the "; A wise Creator adapted this thick, non- conducting, India-rubber-like coating to withstand the tremendous pressure of the water J and to protect the body from the freezing cold. § To keep the water out of the lungs when diving, the blow- holes are provided with valves that, like a cork in a bottle, close more firmly the greater the pressure outside. the lungs, which, cooling, changes to vapor, and in its circling descent resembles a shower of spray. * The tail has often an area of 100 square feet, is exceedingly flexible, and so strong that the whale can spring clear out of the water " like little fish leaping into the air after flies," falling again to the sea with a crash that is heard for miles. t In other animals, as the hog, the fat lies between the skin and the muscles. X The whale often descends to the depth of a mile, where, according to Scoresby, the pressure upon it is equal to 200,000 tons, and wood becomes so watersoaked as not to rise again. § This enonnous bulk of fat is lighter than the water and gives great buoyancy, so that the dead body of a whale floats until the layer of blubbe
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1872
