. Zoölogy [microform] : descriptive and practical. Zoology; Zoologie. Descriptive Zoology. wood, It soon dies. The hole by which the larva enters the wood is hardly larger than a pin head, but as the animal grows it excavates a constantly widening tube, thus itself for life. Just how it burrows is not certainly known. It does not feed upon the wood, the fine sawdust being carried off through the excurrent siphon. Its food consists of microscopic plants and animals, which are brought in by. Fig. 76. Razor Shell Clam. currents, as in the clam, and its only communication with the oute
. Zoölogy [microform] : descriptive and practical. Zoology; Zoologie. Descriptive Zoology. wood, It soon dies. The hole by which the larva enters the wood is hardly larger than a pin head, but as the animal grows it excavates a constantly widening tube, thus itself for life. Just how it burrows is not certainly known. It does not feed upon the wood, the fine sawdust being carried off through the excurrent siphon. Its food consists of microscopic plants and animals, which are brought in by. Fig. 76. Razor Shell Clam. currents, as in the clam, and its only communication with the outer world is through the small hole by which it first entered the wood. Shipworms work rapidly, often completely honeycombing the wood. But no matter how many of them there are in the wood, their tubes nevermterfere with one an6ther, but there is always left a thin partition between. They avoid iron rust, so timbers are protected by driving them thickly with broad-headed nails. The copper sheath-ng of hulls of ships is the best protection. Shipworms caused the famous dam break in Holland at the beginning of the last century. The Razor Shell Clam. — The razor shell clam has a shell somewhat resembling in shape and size the handle of a razor. The foot projects at the anterior end, the siphons at the posterior end. These clams make vertical holes in the sand and can dig rapidly. At low tide the posterior end may be seen projecting from the sand, but unless the col- lector approaches quietly and seizes the clam quickly, it is almost sure to escape. They seem to be very sensitive to vibrations, and probably be- come aware of approach through these rather than through hearing or sight, although they are somewhat sensitive to light. The Salt-water Mussel. — One of the most common marine bivalves is the mussel. The shell is usually dark or purplish, and rather thin. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabi
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1903
