. Elements of zoölogy. Zoology. 148 SEA-SQUIRTS. rigging of vessels, as if by magic. Bebra, the naturalist, wrote a de- scription of one in his cabin by its own light, and read by their phos- phorescence from his cabin-window. Professor Moseley wrote his name upon one with his finger as it lay upon deck ; each letter seemed to ignite, increasing in brilliancy, spreading over the entire animal until it seemed at a white heat. They are found in nearly all the southern seas, and are important factors in the illumination of the submarine world. Salpas.âThese are minute pelagic, free-swimming as-
. Elements of zoölogy. Zoology. 148 SEA-SQUIRTS. rigging of vessels, as if by magic. Bebra, the naturalist, wrote a de- scription of one in his cabin by its own light, and read by their phos- phorescence from his cabin-window. Professor Moseley wrote his name upon one with his finger as it lay upon deck ; each letter seemed to ignite, increasing in brilliancy, spreading over the entire animal until it seemed at a white heat. They are found in nearly all the southern seas, and are important factors in the illumination of the submarine world. Salpas.âThese are minute pelagic, free-swimming as- cidians. There are solitary and chain Salpa ; the former (Fig. 187) are barrel-shaped, even the hoops being repre-. Fig. 187.âDoh'olum, an ascidian allied to the salpa. a, nerve; d, mouth ; £â , oesophagus ; z, stomach ; /, intestine ; r, heart; 11, muscles. sented by circular bands or muscles. In both, the open- ings are at each end, and locomotion is produced by a regular contraction and expansion of the mantle. The salpa in its development affords another example of alter- nate generations. The solitary asexual salpa, by bud- ding, produces a family of chained salpae ; these in turn produce, not buds, but fertilized eggs, that, after pass- ing through several changes, assume the solitary asexual salpa form. Note.âThey are brilliantly luminous, the chains stretching away for great distances, resembling luminous snakes winding their way over the sea. Their light in the darkest night rivals that of the moon upon the 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 Holder, Charles Frederick, 1851-1915; Holder, Joseph Bassett, 1824-1888, joint author. New York : D. Appleton and company
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectzoology, bookyear1884
