. Elements of zoology, to accompany the field and laboratory study of animals. Zoology. NEREIS 191 and structure. Such is the case with some of the round- worms. Some of these are thread-lili;e, live in springs or pools, and are regarded by the uninitiated as ani- mated horsehairs. Others are spindle-shaped, as, for example, the " vinegar eel " and the roundworms that are common in stagnant water. Others live in the food canal, as, for example, the stomach-worm (As'caris) of the horse and the pinworm of man. Others still penetrate into the muscles, and cause great pain and often deat
. Elements of zoology, to accompany the field and laboratory study of animals. Zoology. NEREIS 191 and structure. Such is the case with some of the round- worms. Some of these are thread-lili;e, live in springs or pools, and are regarded by the uninitiated as ani- mated horsehairs. Others are spindle-shaped, as, for example, the " vinegar eel " and the roundworms that are common in stagnant water. Others live in the food canal, as, for example, the stomach-worm (As'caris) of the horse and the pinworm of man. Others still penetrate into the muscles, and cause great pain and often death. Such is the pork- worm (Trichi'na^), which gets into man by means of un- cooked pork, multiplies in the food canal, migrates in great numbers into the muscles and encysts itself there (Fig. 186). The second group that is partly parasitic is that of the flatworms. Some flatworms live free in ponds. They will be found abundantly among plants taken from small ponds in the summer and autumn, and are commonl}^ known as Plana'ria â â (Fig. 187). They may be recognized not onlj' by their flat- tened form, but also by a curious jiroboscis which protrudes from the middle of the under side of the body and bears a mouth at its tip. These creatures have a marvellous power ' thrix, hair. ^ planus, Fig. â Ccrebratulus, a cream-col- ored iiemertean. Head end at upper part of figure ; mouth turned toward observer, proboscis retracted. In- stantaneous photograph of U\'ing worm by W. H. C. 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 Davenport, Charles Benedict, 1866-1944; Davenport, Gertrude Anna Crotty, 1866- joint author. New York, Macmillan
Size: 1354px × 1846px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectzoology, bookyear1911
