On the Origin and Metamorphoses of Insects. Sir John Lubbock
Читать онлайн.| Название | On the Origin and Metamorphoses of Insects |
|---|---|
| Автор произведения | Sir John Lubbock |
| Жанр | Языкознание |
| Серия | |
| Издательство | Языкознание |
| Год выпуска | 0 |
| isbn | 4057664562937 |
18. Egg of Platygaster, showing the central cell.
19. Egg of Platygaster, after the division of the central cell.
20. Egg of Platygaster, more advanced.
21. Egg of Platygaster, more advanced.
22. Egg of Platygaster, showing the rudiment of the embryo.
23. Larva of Platygaster.—mo, mouth; a, antenna; kf, hooked feet; r, toothed process; lfg, lateral process; f, branches of the tail.
24. Larva of another species of Platygaster. (The letters indicate the same parts as in the preceding figure.)
25. Larva of a third species of Platygaster. (The letters indicate the same parts as in the preceding figure.)
26. Larva of Platygaster in the second stage.—mo, mouth; slkf, œsophagus; gsae, supra-œsophagal ganglion; lm, muscles; bsm, nervous system; gagh, rudiments of the reproductive glands.
27. Larva of Platygaster in the third stage.—mo, mouth; ma, mandibles; gsae, supra-œsophagal ganglion; slk, œsophagus; ag, ducts of the salivary glands; bnm, ventral nervous system; sp, salivary glands; msl, stomach; im, imaginal discs; tr, tracheæ; fk, fatty tissue; ed, intestine; ga, rudiments of reproductive organs; ew, wider portion of intestine; ao, posterior opening.
28. Embryo of Polynema.
29. Larva of Polynema.—asch, rudiments of the antennæ; flsch, of the wings; bsch, of the legs; vfg, lateral projections; gsch, rudiments of the ovipositor; fk, fatty tissue.
30. Egg of Phryganea (Mystacides).—A1, mandibular segment; C1-C5, maxillary, labial, and three thoracic segments; D, abdomen.
31. Egg of Phryganea somewhat more advanced.—b, mandibles; c, maxillæ; cfs, rudiments of the three pairs of legs.
32. Egg of Pholcus opilionides, showing the Protozonites.
33. Embryo of Julus.
34. Colony of Bougainvillea fruticosa, natural size, attached to the underside of a piece of floating timber.
35. Portion of the same, more magnified.
36. The Medusa from the same species.
37. Larva of Prawn, Nauplius stage.
38. Larva of Prawn, more advanced, Zoëa stage.
39. Larva of Echino-cidaris œquituberculata seen from above ✕ 6/10.
40. Larva of Echinus ✕ 100.—A, front arm; F, arms of the mouth-process; B, posterior side arm; E1, accessory arm of the mouth-process; a, mouth; a1, œsophagus; b, stomach; b1, intestine; o, posterior orifice; d, ciliated bands; f, ciliated epaulets; c, disc of future Echinus.
41. Comatula rosacea.
42. Larva of Comatula rosacea.
43. Larva of Comatula rosacea, more advanced.
44. Larva of Comatula rosacea, in the Pentacrinus state.
45. Larva of Starfish (Bipinnaria), ✕ 100.
46. Larva of Starfish (Bipinnaria), ✕ 100, seen from the side.—a, mouth; b, œsophagus; c, stomach; c1, intestine.
47. Larva of another Bipinnaria, showing the commencement of the Starfish.—g, canal of the ciliated sac; i, rudiments of tentacles; d, ciliated band.
48. Larva of Moth (Agrotis).
49. Larva of Beetle (Haltica).
50. Larva of Saw-fly (Cimbex).
51. Larva of Julus.
52. Agrotis suffusa.
53. Haltica.
54. Cimbex.
55. Julus.
56. Tardigrade.
57. Larva of Cecidomyia.
58. Lindia torulosa.
59. Prorhynchus stagnalis.
60. Egg of Tardigrade.
61. Egg of Tardigrade, after the yolk has subdivided.
62. Egg of Tardigrade, in the next stage.
63. Egg of Tardigrade, more advanced.
ON THE
ORIGIN AND METAMORPHOSES
OF INSECTS.
CHAPTER I.
THE CLASSIFICATION OF INSECTS.
About forty years ago the civil and ecclesiastical authorities of St. Fernando in Chili arrested a certain M. Renous on a charge of witchcraft, because he kept some caterpillars which turned into butterflies.1 This was no doubt an extreme case of ignorance; it is now almost universally known that the great majority of insects quit the egg in a state very different from that which they ultimately assume; and the general statement in works on entomology has been that the life of an insect may be divided into four periods.
Thus, according to Kirby and Spence,2 “The states through which insects pass are four: the egg, the larva, the pupa, and the imago.” Burmeister,3 also, says that, excluding certain very rare anomalies, “we may observe four distinct periods of existence in every insect—namely, those of the egg, the larva, the pupa, and the imago, or perfect insect.” In fact, however, the various groups of insects differ widely from one another in the metamorphoses they pass through: in some, as in the grasshoppers and crickets, the changes consist principally in a gradual increase of size, and in the acquisition of wings; while others, as for instance the common fly, acquire their full bulk in a form very different from that which they ultimately assume, and pass through a period of inaction in which not only is the whole form of the body altered, not only are legs and wings acquired, but even the internal organs themselves are almost entirely disintegrated and re-formed. It will be my object, after having briefly described these changes, to throw some light on the causes to which they are due, and on the indications they afford of the stages through which insects have been evolved.
The following list gives the orders or principal groups into which the Class Insecta may be divided. I will not, indeed, here enter upon my own views, but will adopt the system given by Mr. Westwood in his excellent “Introduction to the Modern Classification of Insects,” from which also, as a standard authority, most of the figures on Plates I. to IV., when not otherwise acknowledged, have been taken. He divides insects into thirteen groups, and with reference to eight of them it may be said that there is little difference of opinion among entomologists. These orders are by far the most numerous, and I have placed them in capital letters. As regards the other five there is still much difference of opinion. It must also be observed that Prof. Westwood omits the parasitic Anoplura, as well as the Thysanura and Collembola.
ORDERS OF INSECTS ACCORDING TO WESTWOOD.
| 1. Hymenoptera | Bees, Wasps, Ants, &c. |