. Elements of comparative zoology. Zoology. 244 S} ~S TEMA TIC ZOO LOG Y. thread-like; ocelli are always present; the pro thorax moves freely on the mesothorax; the abdomen is ten-jointed, and it usually bears on its tenth somite movable cerci; the ovipositor is large and cannot be withdrawn into the abdomen; the anterior wings serve as covers for the second pair, and these last are folded longitudinally, when at rest, like a fan. Besides these points, which should have been made out by the student, there is another feature not readily dis- covered in the classroom. The young Orthopteran hatch
. Elements of comparative zoology. Zoology. 244 S} ~S TEMA TIC ZOO LOG Y. thread-like; ocelli are always present; the pro thorax moves freely on the mesothorax; the abdomen is ten-jointed, and it usually bears on its tenth somite movable cerci; the ovipositor is large and cannot be withdrawn into the abdomen; the anterior wings serve as covers for the second pair, and these last are folded longitudinally, when at rest, like a fan. Besides these points, which should have been made out by the student, there is another feature not readily dis- covered in the classroom. The young Orthopteran hatches from the egg with all the legs and segments of the adult, which it resembles much in general appearance, except in the following particulars: it is smaller in size, with a dis- proportionately large head, and it lacks the wings character- istic of the full-grown form. It is most voracious, and with much eating increases rapidly in size. But since it is enclosed in a hard outer wall, incapable of growth, it has frequently to cast off this non-elastic 'skin' and to grow a new one, larger than the old. This molting is accom- plished by a splitting of the old skin down the back, and from this hole the animal draws itself, and now, its skin. FIG. 69.—Young grasshopper with the wings just beginning to appear After Emerton. being soft, it can readily increase in size. Gradually, however, the skin becomes thicker and harder, and 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 Kingsley, J. S. (John Sterling), 1854-1929. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1904
