A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . noptera,the wings are outgrowths of the scutal FK;. 1ST. — Development of wings of region of the : 4, portion of body-wall of young larva of Trichostegia ; , With these facts before us we may forming at >• a projection into the hypo- . „ m -, i, and ft, forming thus the speculate as to the probable origin oi first rudiment of the wing. Jf, the parts in .
A text-book of entomology, including the anatomy, physiology, embryology and metamorphoses of insects, for use in agricultural and technical schools and colleges as well as by the working entomologist . noptera,the wings are outgrowths of the scutal FK;. 1ST. — Development of wings of region of the : 4, portion of body-wall of young larva of Trichostegia ; , With these facts before us we may forming at >• a projection into the hypo- . „ m -, i, and ft, forming thus the speculate as to the probable origin oi first rudiment of the wing. Jf, the parts in . „ . , , ,, a larva of nearly full size; «, c, d, b, the the WlUgS Of insects. Hie V16WS heldwell-developed hypodermis of the wing- r> r~\ germ separated fnto two parts iiy r, the by some are those oi (jregenoaur, also penetrating extension of the cuticula ; r, , , T , , -, , . •,-, , mesoderm. a wing-pad of another Phry- adopted by Lubbock, and originally by ganeid freed from its case at its change to 1 p , . 1 . ,-*, , the pupa : /,. ,/, outer layer of the hypo- myself / According to Gegenbaur : derniis (mi of the body-wall; v, innerlayer within nuclei. — After Dewitz, from. The wings must be regarded as homolo-gous with the lamellar tracheal gills, for they do not only agree with them in origin, but also in their connection withtin- bn<ly, and in structure. In being limited to the second and third thoracicsegments they point to a reduction in the number of the tracheal gills. It isquite clear that we must suppose that the wings did not arise as such, but were(liVclnped from organs which had another function, such as the tracheal gills ;I mean to say that such a supposition is necessary, for we cannot imagine thatthe wings functioned as such in the lower stages of their development, andthat they could have been developed by having such a 1 On the transformations of the common house fly, by A. S. Packard, Jr. Pro-ceedings Bnston Society of Natural
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectinsects
