The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . which, as L. C. Miall remarks, is structurally little other than thefly enclosed in a temporary skin. Moreover, in many insects withimperfect metamorphosis the change from larva or (as the later stageof the larva is called in these cases) nymph to imago isabout as greatas the corresponding change in the Holomctabola, as the studentft ill recognize if he recalls the histories of Ephemertdae, Odonata andmale Coccidae. But in none of these latter cases have the wings tobe changed from a position insi
The encyclopædia britannica; a dictionary of arts, sciences, literature and general information . which, as L. C. Miall remarks, is structurally little other than thefly enclosed in a temporary skin. Moreover, in many insects withimperfect metamorphosis the change from larva or (as the later stageof the larva is called in these cases) nymph to imago isabout as greatas the corresponding change in the Holomctabola, as the studentft ill recognize if he recalls the histories of Ephemertdae, Odonata andmale Coccidae. But in none of these latter cases have the wings tobe changed from a position inside the body to become ;:tcrnal andactively functional organs. The diflterence between the nymph orfalse pupa and the true pupa is that in the latter a whole stage isdevoted to the perfecting of the wings and body-wall after the wingshave become external organs; the stage is one m which no food is orcan be taken, however prolonged may be its existence. Amongstinsects with imperfect metamorphosis the nearest approximationsto the true pupa of the Holometabola are to be found in the subimago. aFrom Chiltcnden, Bull. 4 (n 5.) d>. Etl. U3. Dtp}. Afr. Fig. 26.—a. Saw-toothed Grain-Beetle (Sihanus surinamensis) \4, pupa; c, larva, magnified—; d, feeler of larva. of Ephemeridae and in the quiescent or resting stages of Thysanoptera,Aleurodidae and Coccidae. A much more thorough apprc-ciationthan we yet possess of the phenomena in these cases is necessary inorder completely to demonstrate the special characteristics of theholometabolous transformation. But even at present we can cor-rectly state that the true pupa is invariably connected with thetransference of the wings from the interior to the exterior of the cannot but suggest itself that this transference was induced bysome peculiarity as to formation of cuticle, causing the growth of thewings to be directed inwards instead of outwards. We may remarkthat fleas possess no wings, but are understood to possess a tru
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectencyclo, bookyear1910
