Archive image from page 455 of The cyclopædia of anatomy and. The cyclopædia of anatomy and physiology cyclopdiaofana03todd Year: 1847 fixed on the surface of motion at c (fig. 234) ; the anal extremity is drawn forwards to the thoracic segments, from a to b; the trunk is then again extended to d, and a series of the same alternate flexions and extensions is em- ployed to carry the larva onwards. During progression, the Geometrae spin a silken cord, which they fix by the head on the plane of position at each step, thus measuring the dis- tance over which they pass. The use of this «n-<\ is
Archive image from page 455 of The cyclopædia of anatomy and. The cyclopædia of anatomy and physiology cyclopdiaofana03todd Year: 1847 fixed on the surface of motion at c (fig. 234) ; the anal extremity is drawn forwards to the thoracic segments, from a to b; the trunk is then again extended to d, and a series of the same alternate flexions and extensions is em- ployed to carry the larva onwards. During progression, the Geometrae spin a silken cord, which they fix by the head on the plane of position at each step, thus measuring the dis- tance over which they pass. The use of this «n-<\ is in enable them to descend from the d trees, however lofty, on which they feed, and to reascend by the same means, without the necessity of taking a circuitous route, and encountering the inequalities of the trunk and branches. In like manner the Caterpillars of the Cabbage-butterfly weave a ladder of silk on the plane of a glass-window, which serves as a fulcrum for its legs, and thus enables the animal to ascend. Perfect Insects.—The order in which the legs of the Hexapods move in walking or running has been accurately explained by Professor Muller. Whilst watching insects which move slowly, he observed that three of their legs were always moving at the same time; these were advanced and put to the ground, whilst the other three propelled the body of the insect forwards. The feet, which moved simultaneously, were the fore and hindmost foot on one side, and the middle foot of the opposite side; then the fore and hind foot on this side, and the middle one of the other side, so that in two steps all the six feet are set in motion. In the first movement, whilst the legs, 1, 2', 3, (Jig. 235) Fig. 235.
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Keywords: 1840, 1847, anatomy, archive, book, bookauthor, bookdecade, bookpublisher, booksponsor, booksubject, bookyear, drawing, historical, history, illustration, image, london_sherwood_gilbert_and_piper, mblwhoi_library, page, physiology, picture, print, reference, todd_robert_bentley_1809_1860, vintage, zimmermann_a_albrecht_b_1860, zoology
