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- The common round-web spider, Epeira vulgaris of Hentz (Under Side)
The body is seen to be divided into two parts, connected only by the narrow joint, A, just behind the last pair of legs. The front half of the body, called the thorax, contains the stomach, the central part of the nervous system, and the large muscles which work the legs and jaws. The hinder half, the abdomen, contains the intestine, the breathing-organs, the principal circulating-vessels, the organs of reproduction, and the spinning-organs. Connected with the thorax are six pairs of limbs, four pairs of legs, B B B B, a pair of palpi, C, and a pair of mandibles, D. - Egg-capsule of P. orientalis
A external view B opened C end view. The eggs of the Cockroach are laid sixteen together in a large horny capsule. This capsule is oval, with roundish ends, and has a longitudinal serrated ridge, which is uppermost while in position within the body of the female. The capsule is formed by the secretion of a “colleterial” gland, poured out upon the inner surface of a chamber (vulva) into which the oviducts lead. The secretion is at first fluid and white, but hardens and turns brown on exposure to the air. In this way a sort of mould of the vulva is formed, which is hollow, and opens forwards towards the outlet of the common oviduct. Eggs are now passed one by one into the capsule; and as it becomes full, its length is gradually increased by fresh additions, while the first-formed portion begins to protrude from the body of the female. When sixteen eggs have descended, the capsule is closed in front, and after an interval of seven or eight days, is dropped in a warm and sheltered crevice. In Periplaneta orientalis it measures about ·45 in. by ·25 in. - Normal position of the larvæ of Culex and Anopheles in the water
(a) Normal position of the larvæ of Culex and Anopheles in the water. Culex, left; Anopheles, middle; Culex pupa, right hand figure - Mosquito
Anopheles punctipennis. Female - Argus persicus. Capitulum of male
Until recently, the ticks attracted comparatively little attention from entomologists. Since their importance as carriers of disease has been established, interest in the group has been enormously stimulated and now they `rank` second only to the mosquitoes in the amount of detailed study that has been devoted to them. The ticks are the largest of the Acarina. They are characterized by the fact that the hypostome, or "tongue" is large and file-like, roughened by sharp teeth. - A whip-scorpion
The tailed whip-scorpions, belonging to the family Thelyphonidæ, are represented in the United States by the giant whip-scorpion Mastigoproctus giganteus, which is common in Florida, Texas and some other parts of the South. In Florida, it is locally known as the "grampus" or "mule-killer" and is very greatly feared. There is no evidence that these fears have any foundation, and Dr. Marx states that there is neither a poison gland nor a pore in the claw of the chelicera. - Larva of Forficula
Larva of Forficula - Anopheles quadrimaculatus mosquito
Anopheles quadrimaculatus mosquito, male and female - Longitudinal section of Female Cockroach
Longitudinal section of Female Cockroach, to show the position of the principal organs. Oe œsophagus S.gl, salivary gland S.r salivary reservoir Cr crop G gizzard St, chylific stomach R rectum Ht heart N.C nerve-cord Uses Of the uses to which Cockroaches have been put we have little to say. They constitute a popular remedy for dropsy in Russia, and both cockroach-tea and cockroach-pills are known in the medical practice of Philadelphia. Salted Cockroaches are said to have an agreeable flavour which is apparent in certain popular sauces. - Upper Side of Epeira Vulgaris
The head is not separated from the rest of the body, as in insects, but forms, with the thorax, one piece. On the front of the head are eight eyes, Q, which are differently arranged in different spiders. On the abdomen are several pairs of dark smooth spots, which mark the ends of muscles extending downward through the abdomen. The markings of this spider are very complicated. The spot on the middle of the front of the abdomen is a very common one, and, in some spiders, extends the whole length of the body. The waved lines on each side are also common, and, in long-bodied spiders, often form two bright-colored stripes, or rows of spots, running nearly straight the whole length of the abdomen. - A flesh fly
A flesh fly - A true scorpion
The true scorpions are widely distributed throughout warm countries and everywhere bear an evil reputation. According to Comstock (1912), about a score of species occur in the Southern United States. These are comparatively small forms but in the tropics members of this group may reach a length of seven or eight inches. They are pre-eminently predaceous forms, which lie hidden during the day and seek their prey by night. The scorpions possess large pedipalpi, terminated by strongly developed claws, or chelæ. They may be distinguished from all other Arachnids by the fact that the distinctly segmented abdomen is divided into a broad basal region of seven segments and a terminal, slender, tail-like division of five distinct segments - Diagram of a longitudinal section of a mosquito
It is well known that mosquitoes, when they bite, inject into the wound a minute quantity of poison. The effect of this varies according to the species of mosquito and also depends very much on the susceptibility of the individual. Soon after the bite a sensation of itching is noticed and often a wheal, or eminence, is produced on the skin, which may increase to a considerable swelling. The scratching which is induced may cause a secondary infection and thus lead to serious results. Some people seem to acquire an immunity against the poison. The purpose of this irritating fluid may be, as Reaumur suggested, to prevent the coagulation of the blood and thus not only to cause it to flow freely when the insect bites but to prevent its rapid coagulation in the stomach. Obviously, it is not developed as a protective fluid, and its presence subjects the group to the additional handicap of the vengeance of man. As to the origin of the poison, there has been little question, until recent years, that it was a secretion from the salivary glands. Macloskie (1888) showed that each gland is subdivided into three lobes, the middle of which differs from the others in having evenly granulated contents and staining more deeply than the others. - Foot of Attus Mystaceus
In many spiders a brush of hairs takes the place of the middle claw, as in the jumping spiders. Spiders with these brushes on their feet can walk up a steep surface, or under a horizontal one, better than those who have three claws. - Section of Epeira Vulgaris
Section of a spider to show the arrangement of the internal organs: a, b, upper and under lips of the mouth; c, c, the œsophagus; d, f, upper and under muscles of the sucking-stomach; e, stomach; g, g, ligaments attached to diaphragm under the stomach; J, lower nervous ganglion; k, upper ganglion; l, l, nerves to the legs and palpi; m, branches of the stomach; n, poison-gland; o, intestine; p, heart; R, air-sac; S, ovary; t, air-tube; u, spinning-glands. The intestine, o, continues backward through the abdomen to the anus, in the little knob behind the spinnerete. The brown mass which surrounds the intestine, and fills the abdomen above it, is supposed to be a secreting-organ discharging into the intestine at several points. - Blossom of Cucurbita
Mother-Aphis and Her Army of Children on Tube Whilst engaged some few years ago in the study of the species that affects the blossoms of one of our gourds—the Cucurbita ovifera of botanists—certain phenomena were observed, which promised an easy and speedy solution of the problem. Gathered in compact masses, like companies of soldiery preparing for a foray, hundreds of aphides were seen, busily feeding, all over the flowers. There were old and young, not an indiscriminate mingling of ages and sizes, but an orderly arrangement of families, each family preceded by its own appropriate head. First came the very young of each family, only to be followed by those that were older, leaving the oldest of all to lead up the rear. - Mygale Hentzii
MYGALIDÆ This family includes the largest known spiders. The body is usually very hairy and dark-colored. Most species have only four spinnerets; and one pair of these are long, and are turned up behind the abdomen. They have four air-sacs under the front of the abdomen, instead of two, as other spiders. Their mandibles are very large, and work up and down, instead of sidewise. The eyes are collected together on the front of the head. They live only in warm countries. Specimens from South America are exhibited in every natural history museum. The figure represents Mygale Hentzii, a species living in Arizona and Texas. - Syrian Ants
The Ant is mentioned twice in the Old Testament, both times in the Book of Proverbs (vi. 6 and xxx. 25). Ants are characterized as being exceeding wise, and in both passages are commended for their diligence in preparing their food in the summer, thus by their fore-sight providing for their winter sustenance. Such is at least the` obvious implication contained in the text. This habit was, and is still, contradicted by some writers, from their knowledge of the ways of European ants, which are dormant in the winter, and therefore stand in no need of food. - Dysderidæ
Dysdera Interrita A small family of spiders with only six eyes. They have also four breathing-holes in the front of the abdomen; but one pair leads to branched tubes instead of sacs. They are usually found under stones, with their legs drawn up close to their bodies, but can move very quickly when so inclined. Very few species are known, and none are common, in North America. At bottom of figure are the eyes as seen from in front. - Flea
The strength and beauty of this small creature, had it no other relation at all to man, would deserve a description. For its strength, the Microscope is able to make no greater discoveries of it then the naked eye, but onely the curious contrivance of its leggs and joints, for the exerting that strength, is very plainly manifested, such as no other creature, I have yet observ'd, has any thing like it; for the joints of it are so adapted, that he can, as 'twere, fold them short one within another, and suddenly stretch, or spring them out to their whole length, that is, of the fore-leggs, the part A, of the Scheme, lies within B, and B within C, parallel to, or side by side each other; but the parts of the two next, lie quite contrary, that is, D without E, and E without F, but parallel also; but the parts of the hinder leggs, G, H and I, bend one within another, like the parts of a double jointed Ruler, or like the foot, legg and thigh of a man; these six leggs he clitches up altogether, and when he leaps, springs them all out, and thereby exerts his whole strength at once. - Simulium venustum
The Simuliidæ, or black flies, are small, dark, or black flies, with a stout body and a hump-back appearance. The antennæ are short but eleven-segmented, the wings broad, without scales or hairs, and with the anterior veins stout but the others very weak. The mouth-parts are fitted for biting. - An American tarantula
n popular usage, the term "tarantula" is loosely applied to any one of a number of large spiders. The famous tarantulas of southern Europe, whose bites were supposed to cause the dancing mania, were Lycosidæ, or wolf-spiders. Though various species of this group were doubtless so designated, the one which seems to have been most implicated was Lycosa tarantula (L.). On the other hand, in this country, though there are many Lycosidæ, the term "tarantula" has been applied to members of the superfamily Avicularoidea, including the bird-spiders. - A medieval method of combating the plague. The persecution of the anointers in Milan in 1630
In Milan the visitation of 1630 was credited to the so-called anointers,—men who were supposed to spread the plague by anointing the walls with magic ointment—and the most horrible tortures that human ingenuity could devise were imposed on scores of victims, regardless of `rank` or of public service. Manzoni's great historical novel, "The Betrothed" has well pictured conditions in Italy during this period. - Louse of the Cat
- Auchmeromyia luteola
Auchmeromyia luteola, the Congo floor maggot. This is a muscid of grewsome habits, which has a wide distribution throughout Africa. The fly deposits its eggs on the ground of the huts of the natives. - Argynnis Aphrodite
- Antennæ of Goniodes
- The Pursuit
Birds chasing insects - On the Watch
Bird watching a butterfly - Bees in Clover