Butterflies: Their Structure, Changes and Life-histories, with Special Reference to American Forms. Being an Application of the "Doctrine of Descent" to the Study of Butterflies. With an Appendix of Practical Instructions

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H. Holt, 1881 - 322 páginas
 

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Página 211 - At first the scales growing on the membrane upon or near the veins show a freer development of pigmentary matter, and in this manner would arise a kind of primary or fundamental pattern, namely, a pale ground with darker linear markings, following the course of the veins (Pieris cratcegi).
Página 58 - Rudimentary organs may be compared with the letters in a word, still retained in the spelling, but become useless in the pronunciation, but which serve as a clue for its derivation.
Página 216 - ... ocellus, and this results from the contraction of the irregular blotches of colour. In another series of specimens a gradation can be followed from excessively minute white dots, surrounded by a scarcely visible black line, into perfectly symmetrical and large ocelli
Página 250 - ... and the suddenness with which it can be thrown out, we must, I think, be led to the conclusion that it serves as a protection to the larva, by startling and frightening away some enemy when about to seize it, and is thus one of the causes which has led to the wide extension and maintained the permanence of this now dominant group. Those who believe that such peculiar structures can only have arisen by very minute successive variations, each one advantageous to its possessor, must see, in the...
Página 277 - The zinc pan might be made 6 or 8 inches deep, and the lower half filled with sand, so as to keep the whole moist for a greater length of time. "A dozen such cages will furnish room for the annual breeding of a great number of species, as several having different habits and appearance, and which there is no danger of confounding, may be simultaneously fed in the same cage.
Página 199 - Deschamps called them plumules, from their feathery lips ; but the term is utterly inappropriate to most of them ; and their form is so varied that only some word expressing their masculine character should be accepted, since this is their single common peculiarity. These androconia are very capricious in their occurrence ; a number of allied genera may possess them, while a single genus, as closely allied, may be quite destitute. This is true throughout the butterflies, and yet there are large groups...
Página 285 - The other ends are bent and beaten into two square sockets (/) which fit to a nut sunk and soldered into one end of a brass tube (d). When so fitted, they are secured by a large-headed screw (e) threaded to fit into the nut-socket, and with a groove wide enough to receive the back of a common pocket knife blade.
Página 276 - M. c. 201. 3 (e) , and the quinine bottle is for the reception of the food-plant. The cage admits of abundant light and air, and also of the easy removal of the excrement and frass which fall to the ground ; while the insects in transforming enter the ground or attach themselves to the sides or the cap, according to their habits. The most convenient dimensions I find to be 12 inches square...
Página 191 - The facts, as stated by him, are these : There are twelve species of the genus discussed by him;* of these, nine have gaudy males and plain females ; one has plain male and plain female ; and two have gaudy males and gaudy females. The plain females, he adds, "resemble each other in their general type of coloration, and likewise resemble both sexes in several allied genera, found in various parts of the world." To examine this case fairly would need a large collection of exotic butterflies. If we...

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