. A manual for the study of insects. Insects. HEXAPODA. 67 cles, through which honey-dew is excreted : these are com- monly called honey-tubes ; they are also termed cornicleSy nectaries^ or siphuncles. The Internal Anatomy of Insects. {For adva7iced students.) As has been shown in the preceding pages, the body-wall serves as a skeleton, being hard, and giving support to the other organs of the body. This skeleton may be represented, therefore, as a hollow cylinder. We have now to consider the arrangement and the general form of the organs contained in this cylinder. For the details of the str
. A manual for the study of insects. Insects. HEXAPODA. 67 cles, through which honey-dew is excreted : these are com- monly called honey-tubes ; they are also termed cornicleSy nectaries^ or siphuncles. The Internal Anatomy of Insects. {For adva7iced students.) As has been shown in the preceding pages, the body-wall serves as a skeleton, being hard, and giving support to the other organs of the body. This skeleton may be represented, therefore, as a hollow cylinder. We have now to consider the arrangement and the general form of the organs contained in this cylinder. For the details of the structure of th . internal organs the student is referred to more special works. The accompanying diagram (Fig. 80), which represents a vertical, longitudinal section of the body, will enable the student to gain an idea of the relative position of some of the more important organs. The parts shown in the diagram are as follows: The body-wall, or skeleton. Fig. 80.—Diagram showing- the relation of the internal organs. {s); this is made up of a series of overlapping segments ; that part of it between the segments is thinner, and is not hardened with chitine, thus remaining flexible and allowing for the movements of the body. Just within the body-wall, and attached to it, are represented a few of the muscles {m); it will be seen that these muscles are so arranged that the contraction of those on the lower side of the body would bend it down, while the contraction of those on the opposite side would act in the opposite direction. The alimentary canal {a) occu- pies the centre of the body, and extends from one end to the other. The heart {h) is a tube open at both ends, and lying between the alimentary canal and the muscles of the back. The central part of the nervous system {n) is a series of small masses of nervous matter connected by two longitudinal cords: one of these masses, the brain, lies in the head above the alimentary canal; the others are situated,. Please note that these
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinsects, bookyear1895
