Pharyngeal syringe or salivary pump of Fulgora maculata
Accessory to the salivary apparatus there is on the ventral side of the head, underneath the pharynx, a peculiar organ which the Germans have called the "Wanzenspritze," or syringe. The accompanying figure of the structure in Fulgora maculata shows its relation to the ducts of the salivary glands and to the beak. It is made up of a dilatation forming the body of the pump, in which there is a chitinous piston. Attached to the piston is a strong retractor muscle. The function of the salivary pump is to suck up the saliva from the salivary ducts and to force it out through the beak.
Culex larva showing details of external structure
The larvæ are elongate, with the head and thorax sharply distinct. The larval antennæ are prominent, consisting of a single cylindrical and sometimes curved segment. The outer third is often narrower and bears at its base a fan-shaped tuft of hairs, the arrangement and abundance of which is of systematic importance. About the mouth are the so-called rotary mouth brushes, dense masses of long hairs borne by the labrum and having the function of sweeping food into the mouth. The form and arrangement of thoracic, abdominal, and anal tufts of hair vary in different species and present characteristics of value. On either side of the eighth abdominal segment is a patch of scales varying greatly in arrangement and number and of much value in separating species. Respiration is by means of tracheæ which open at the apex of the so-called anal siphon, when it is present. In addition, there are also one or two pairs of tracheal gills which vary much in appearance in different species. On the ventral side of the anal siphon is a double row of flattened, toothed spines whose number and shape are likewise of some value in separating species. They constitute the comb or pecten.
Culicoides guttipennis - mouth parts of adult
Of the twenty or more species of this genus occurring in the United States the following are known to bite: C. cinctus, C. guttipennis, C. sanguisuga, C. stellifer, C. variipennis, C. unicolor.
Larva of Auchmeromyia luteola
The whitish larvæ on hatching are slightly flattened ventrally, and each segment bears posteriorly three foot-pads transversely arranged. At night the larvæ find their way into the low beds or couches of the natives and suck their blood.
Larva of Xenopsylla cheopis
Dermatophilus penetrans
The chigoes, or true chiggers, are the most completely parasitic of any of the fleas. Of the dozen or more known species, one commonly attacks man. This is Dermatophilus penetrans, more commonly known as Sarcopsylla penetrans or Pulex penetrans. This species occurs in Mexico, the West Indies, Central and South America. The males and the immature females of Dermatophilus penetrans closely resemble those of other fleas. They are very active little brown insects about 1-1.2 mm. in size, which live in the dust of native huts and stables, and in dry, sandy soil. In such places they often occur in enormous numbers and become a veritable plague.
Larva of a flesh fly (Sarcophaga) - Caudal aspect - Anterior stigmata. Pharyngeal skeleton
Sarcophagidæ—The larvæ of flies of this family usually feed upon meats, but have been found in cheese, oleomargerine, pickled herring, dead and living insects, cow dung and human feces. Certain species are parasitic in insects. Higgins (1890) reported an instance of "hundreds" of larvæ of Sarcophaga being vomited by a child eighteen months of age. There was no doubt as to their origin for they were voided while the physician was in the room. There are many other reports of their occurrence in the alimentary canal. We have recorded elsewhere (Riley, 1906) a case in which some ten or twelve larvæ of Sarcophaga were found feeding on the diseased tissues of a malignant tumor. The tumor, a melanotic sarcoma, was about the size of a small walnut, and located in the small of the back of an elderly lady.
The house or typhoid fly (Musca domestica)
The house-fly breeds by preference in horse manure. Indeed, It has been found that they would develop in almost any fermenting organic substance. Thus, they have been bred from pig, chicken, and cow manure, dirty waste paper, decaying vegetation, decaying meat, slaughter-house refuse, sawdust-sweepings, and many other sources. A fact which makes them especially dangerous as disease-carriers is that they breed readily in human excrement.
Stomoxys calcitrans - adult, larva, puparium and details
Stomoxys calcitrans, the stable-fly—It is a popular belief that house-flies bite more viciously just before a rain. As a matter of fact, the true house-flies never bite, for their mouth-parts are not fitted for piercing. The basis of the misconception is the fact that a true biting fly, Stomoxys calcitrans , closely resembling the house-fly, is frequently found in houses and may be driven in in greater numbers by muggy weather. From its usual habitat this fly is known as the "stable-fly" or, sometimes as the "biting house-fly."
Filaria in the muscles and labium of Culex
When the blood of an infested individual is sucked up and reaches the stomach of such a mosquito, the larvæ, by very active movements, escape from their sheaths and within a very few hours actively migrate to the body cavity of their new host and settle down primarily in the thoracic muscles. There in the course of sixteen to twenty days they undergo a metamorphosis of which the more conspicuous features are the formation of a mouth, an alimentary canal and a trilobed tail. At the same time there is an enormous increase in size, the larvæ which measured .3 mm. in the blood becoming 1.5 mm. in length. This developmental period may be somewhat shortened in some cases and on the other hand may be considerably extended. The controlling factor seems to be the one of temperature. The transformed larvæ then reenter the body cavity and finally the majority of them reach the interior of the labium. A few enter the legs and antennæ, and the abdomen, but these are wanderers which, it is possible, may likewise ultimately reach the labium, where they await the opportunity to enter their human host.
Trypanosoma brucei
By trypanosomiasis is meant a condition of animal parasitism, common to man and the lower animals, in which trypanosomes, peculiar flagellate protozoa, infest the blood. Depending upon the species, they may be harmless, producing no appreciable ill-effect, or pathogenic, giving rise to conditions of disease. A number of these are known to be transferred by insects. The trypanosomes are elongated, usually pointed, flagellated protozoa in which the single flagellum, bent under the body, forms the outer limit of a delicate undulating membrane. It arises near one end of the organism from a minute centrosome-like body which is known as the blepheroplast, and at the opposite end extends for a greater or less distance as a free flagellum. Enclosing, or close beside the blepheroplast is the small kinetonucleus. The principal nucleus, round or oval in form, is situated near the center of the body. Asexual reproductions occurs in this stage, by longitudinal fission, the nucleus and the blepheroplast dividing independently of one another. From the blepheroplast of one of the daughter cells a new flagellum is formed.
Ornithodoros moubata
(a) Anterior part of venter (b) second stage nymph (c) capitulum (d) dorsal aspect of female (e) ventral aspect of female (f) ventral aspect of nymph (g) capitulum of nymph Ornithodoros moubata, the carrier of African relapsing fever, or "tick-fever," is widely distributed in tropical Africa, and occurs in great numbers in the huts of natives, in the dust, cracks and crevices of the dirt floors, or the walls. It feeds voraciously on man as well as upon birds and mammals. Like others of the Argasidæ, it resembles the bed-bug in its habit of feeding primarily at night. Dutton and Todd observed that the larval stage is undergone in the egg and that the first free stage is that of the octopod nymph.
Spirochæta gallinarum. After Hindle.
Spirochætosis of Fowls—One of the best known of the spirochætes transmitted by arthropods is Spirochæta gallinarum, the cause of a very fatal disease of domestic fowls in widely separated regions of the world. According to Nuttall, it occurs in Southeastern Europe, Asia, Africa, South America and Australia. In 1903, Marchoux and Salimbeni, working in Brazil, made the first detailed study of the disease, and showed that the causative organism is transmitted from fowl to fowl by the tick Argas persicus. They found that the ticks remained infective for at least five months. Specimens which had fed upon diseased birds in Brazil were sent to Nuttall and he promptly confirmed the experiments.
The Roadside Inn
The Kitchen of a Country Inn, 1797
The Kitchen of a Country Inn, 1797: showing the Turnspit Dog. (From the engraving after Rowlandson)
The Oldest Inhabited house in England
The “Fighting Cocks” inn at St. Albans, down by the river Ver, below the Abbey, claims to be—not the oldest inn—but the oldest inhabited house, in the kingdom: a pretension that does not appear to be based on anything more than sheer impudence.
The “Dick Whittington,” Cloth Fair
The City of London’s oldest licensed inn is, by its own claiming, the “Dick Whittington,” in Cloth Fair, Smithfield, but it only claims to have been licensed in the fifteenth century, when it might reasonably—without much fear of contradiction—have made it a century earlier. This is an unusual modesty, fully deserving mention. It is only an “inn” by courtesy, for, however interesting and picturesque the grimy, tottering old lath-and-plaster house may be to the stranger, imagination does not picture any one staying either in the house or in Cloth Fair itself while other houses and other neighbourhoods remain to choose from; and, indeed, the “Dick Whittington”[Pg 6] does not pretend to be anything else than a public-house. The quaint little figure at the angle, in the gloom of the overhanging upper storey, is one of the queer, unconventional imaginings of our remote forefathers, and will repay examination.
“Ye Olde Rover’s Return,” Manchester
The tottering, crazy-looking tavern called “Ye Olde Rover’s Return,” on Shude Hill, claiming to be the “oldest beer-house in the city,” and additionally said once to have been an old farmhouse “where the Cow was kept that supplied Milk to The Men who built the ‘Seven Stars"
Seven Stars
The famous “Seven Stars”, in Withy Grove, proudly bearing on its front the statement that it has been licensed over 560 years, and is the oldest licensed house in Great Britain.
An Ale-stake
The bibulium, that is to say, the ale-house or tavern, displayed its sign for all men to see: the ivy-garland, or wreath of vine-leaves, in honour of Bacchus, wreathed around a hoop at the end of a projecting pole. This bold advertisment of good drink to be had within long outlasted Roman times, and indeed still survives in differing forms, in the signs of existing inns. It became the “ale-stake” of Anglo-Saxon and middle English times. The traveller recognised the ale-stake at a great distance, by reason of its long pole—the “stake” whence those old beer-houses derived their name—projecting from the house-front, with its mass of furze, or garland of flowers, or ivy-wreath, dangling at the end. But the ale-houses that sold good drink little needed such signs, a circumstance that early led to the old proverb, “Good wine needs no bush.”
Elynor Rummyng
A hundred and fifty years later than Piers Plowman we get another picture of an English ale-house, by no less celebrated a poet. This famous house, the “Running Horse,” still stands at Leatherhead, in Surrey, beside the long, many-arched bridge that there crosses the river Mole at one of its most picturesque reaches. It was kept in the time of Henry the Seventh by that very objectionable landlady, Elynor Rummyng, whose peculiarities are the subject of a laureate’s verse. Elynor Rummyng, and John Skelton, the poet-laureate who hymned her person, her beer, and her customers, both flourished in the beginning of the sixteenth century. Skelton, whose genius was wholly satiric, no doubt, in his Tunning (that is to say, the brewing) of Elynor Rummyng, emphasised all her bad points, for it is hardly credible that even the rustics of the Middle Ages would have rushed so enthusiastically for her ale if it had been brewed in the way he describes.
The 'Running Horse,' Leatherhead
A hundred and fifty years later than Piers Plowman we get another picture of an English ale-house, by no less celebrated a poet. This famous house, the “Running Horse,” still stands at Leatherhead, in Surrey, beside the long, many-arched bridge that there crosses the river Mole at one of its most picturesque reaches. It was kept in the time of Henry the Seventh by that very objectionable landlady, Elynor Rummyng, whose peculiarities are the subject of a laureate’s verse.
The Last Days of the 'Swan with Two Necks'
The “Swan with Two Necks,” whence many coaches set out, until the end of such things, was often known by waggish people as the “Wonderful Bird,” and obtained its name from a perversion of the “Swan with Two Nicks”: swans that swam the upper Thames and were the property of the Vintners’ Company being marked on their bills with two nicks, for identification. Lad Lane is now “Gresham Street,” but, apart from its mere name, is a lane still; but the old buildings of the “Swan with Two Necks” were pulled down in 1856.