. The transformations (or metamorphoses) of insects. Insects; Insects; Myriapoda; Arachnida; Crustacea. 12 TRANSFORMA TIONS OF INSECTS. branous space is to be observed on either side of the body between them. Moreover, each arch is formed of two side halves, and there is often a very distinct line of separation to be noticed between the portions of the arches, and also a mark which occu- pies this position on the head and along every segment of the body of the grub or caterpillar. This middle or median line is well seen in the immature Calosoma sycophanta. (See page 15.) The segments of the ab
. The transformations (or metamorphoses) of insects. Insects; Insects; Myriapoda; Arachnida; Crustacea. 12 TRANSFORMA TIONS OF INSECTS. branous space is to be observed on either side of the body between them. Moreover, each arch is formed of two side halves, and there is often a very distinct line of separation to be noticed between the portions of the arches, and also a mark which occu- pies this position on the head and along every segment of the body of the grub or caterpillar. This middle or median line is well seen in the immature Calosoma sycophanta. (See page 15.) The segments of the abdomen, which are not provided with true legs, appear to be at first nine in number, and there are some larvae which have twelve or more of them. Now, on com- paring the segments of the larva, chrysalis, and perfect insect of the same species, it is noticed that the changes in the form of the. CHRYSALIS OF Sphinx ligustri. insect are not brought about by an alteration in the consistence of the integuments only, but by a diminution in the number of the rings or segments. It is true that this diminution is rather deceptive in its appearance, for there has not been any fading away of the segments, but really a union and a consolidation of several in one or more single and separate pieces. Thus it is not uncommon for the first rings of the abdomen to become united to the last segment of the thorax or body, or for several of them to conjoin and leave very faint traces of their former distinctness. Take as an example a kind of lepidopterous insect—a moth-^ whose metamorphosis, so far as regards the shape of the caterpillar and perfect insect is less than is usual. The large Attacus pavonia major is admirably adapted for our purpose. " The abdomen of the caterpillar commences at the fourth seg- ment of the body, as in all other insects, and is formed of nine nearly equal rings; the last but one is, however, shorter than the others,. Please note that these images are extracted fr
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Keywords: ., bookcentury1800, bookdecade1870, booksubjec, booksubjectcrustacea
