. Animal life as affected by the natural conditions of existence. Animal ecology. 156 THE INFLUENCE OF INANIMATE SURROUNDINGS. by the absence of spines on the lobes of the tail, the small size of these lobes, and the relatively large size of the branchial appendages of the legs. Schuiankewitsch showed that it was possible to raise a brood of Artemia MUhausenii from Artemia salina, which lived in salt water of 4° Beaume, by gradually raising the percentage of salt to 25° B. This transformation occurs very gradually, and only in the course of several gene- rations. He observed the same process a
. Animal life as affected by the natural conditions of existence. Animal ecology. 156 THE INFLUENCE OF INANIMATE SURROUNDINGS. by the absence of spines on the lobes of the tail, the small size of these lobes, and the relatively large size of the branchial appendages of the legs. Schuiankewitsch showed that it was possible to raise a brood of Artemia MUhausenii from Artemia salina, which lived in salt water of 4° Beaume, by gradually raising the percentage of salt to 25° B. This transformation occurs very gradually, and only in the course of several gene- rations. He observed the same process also in a free state of nature. A dam which divided a lake containing salt water of 4° B. from another where the water marked 25° B. gave way in the year 1871, so that the density of the water in the lower lake fell to 8° B. At the same time numb3rless individuals of. Fig. 41.—«, slagnalis ; b, Artemia salina. Artemia salina were carried through to the lower lake by the flood, and there they soon settled and propagated. After the dam was repaired the saltness of the water in the lower lake naturally increased again; in 1872 it had risen to 14° B., in 1873 to 18° B., and by the end of September 1874 it had reached its old mark of 25° B. During this period the Artemia salina that had migrated had gradually become transformed into Artemia MUJtausenii. The stages of transformation, as they were actually successively observed one after another by Schmanke- witsch, are here given hi a woodcut (fig. 42) copied from Schmankewitsch's drawing. He also conducted the converse experiment with perfect. 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 Semper, C. (Carl), 1832-1893. New York, D. Appleton and Co.
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Keywords: ., bookcentury1800, bookdecade1880, bookpublishernewyo, bookyear1881
