Sir A. E. Shipley

“ Flies become sexually mature in a week or ten days after emerging from the chrysalis-case, and are capable of depositing their eggs four days after mating, so that if the conditions be indeed favourable the whole development from the egg to the perfect fly may be accomplished in nine or ten days, and the second generations are able to lay their eggs ten days later. The appalling fecundity of such an insect explains the fact that in the hotter parts of the world nearly every edible thing seems to be covered with them. ”

“ It is not only those insects that destroy the continuity of our soldiers’ integument which play a part in war. It has been well said that an army marches on its stomach; and the admirable commissariat arrangements which have been so distinctive a feature of the British Expeditionary Force during the present war are the result of much patient care and attention during times of peace. ”

“ Unlike the lice and the bed-bug, the fly like the flea, passes through a complete metamorphosis—egg, larva, pupa, and imago. It will breed in almost any rotten matter, whether vegetable or animal, and it breeds most successfully, as Gordon Hewitt has pointed out, when certain processes of organic fermentation are taking place in its breeding-place. Probably the fermentation has a favourable effect upon the food of the larvae. Undoubtedly the place most readily selected by the female for laying her eggs is stable-manure. ”

“ Making their tortuous way towards [158] the human skin, they wriggle about under the under-clothing until they attain almost any position on the body they wish to take up. Their bite is absolutely painless, and it is usual for the human sufferer to become aware that he has been bitten by these silent and tireless leeches when he notices sundry streams of blood running down his body when he at last has the opportunity of undressing. ”

“ We will confine our attention to the second genus, Pediculus, which contains two species parasitic upon man— (Pediculus capitis) the hair-louse and (Pediculus vestimenti) the body-louse. Both of these are extremely difficult to rear in captivity, though in their natural state they abound and multiply to an amazing degree.
Wherever human beings are gathered together in large numbers, with infrequent opportunities of changing their clothes, P. vestimenti is sure to spread. It does not [3] arise, as the uninformed think, from dirt, though it flourishes best in dirty surroundings. ”

“ These ‘Minor Horrors of War,’ and many besides, have for the moment been neglected in favour of certain others which attack the bodies, the food, or the accoutrements of the men who are giving all that they have to give, even unto their lives, for their homes and for their country. ”

“ The female swells enormously when gorged, sometimes becoming as large as a filbert, or even a small walnut. These ticks are seldom parasites of one particular host, but attack many mammals indifferently. They have many natural enemies: amongst the most important of which are certain hemipterous insects whose female attacks the nymph of the Ixodes, and lays within the body of the tick a number of eggs which develop inside [120] the nymph until they reach the adult stage, when they make their escape through an orifice, generally at the hind end, leaving behind them the dead body of their host. ”

“ In the walls of the pharynx and the neighbouring parts are numerous large unicellular glands which secrete an anti-coaguline fluid which prevents the blood of the host clotting, so that even when the leech moves its mouth to another point the triradiate puncture continues to ooze. The same anti-coaguline secretion no doubt prevents the blood coagulating [141] in the enormous crop of the leech in which this meal of blood is stored. Opportunities for a meal presumably occur but seldom in nature, and the leech is the ‘boa-constrictor’ of the invertebrate world. ”

“ Fleas are temporarily parasitic on many mammals and birds, but some mammals and some birds are much freer from fleas than others. As the flea is only on its host for part of the time, it has to put in the rest of its existence in some other place, and this, in the case of the human flea, is usually the floor, and in the case of bird-fleas the nest ”

“ As a rule, each host has its own species of flea; but though for the most part Pulex irritans is confined to man it is occasionally found on cats and dogs, whilst conversely the cat- and dog-fleas (Ctenocephalus felis and Ct. canis) from time to time attack man.
The bite of the flea is accompanied by the injection of the secretions of the so-called salivary glands of the insect, and this secretion retards the coagulation of the victim’s blood, [38] stimulates the blood-flow, and sets up the irritation we have all felt. ”

“ In the East, where many of our Territorial regiments are now stationed, we come across another species of leech even more injurious to mankind than Limnatis nilotica. This Asiatic leech is known as Haemadipsa zeylanica, and is one of a considerable number of leeches which have left the water, their natural habitat, and have taken to live on land.
From India and Ceylon, throughout Burma, Cochin China, Formosa to Japan, the Philippines, and the Sunda Island, this terrible, and at certain elevations ubiquitous, pest is spread. It lives upon damp and moist earth. ”

“ Monkeys in nature are cleanly in their habits; and although in confinement occasionally a human flea attacks them, and although occasionally a chigo bores into the toes of a gorilla or chimpanzee, ‘speaking generally, it may be said that no fleas have been found truly parasitic on monkeys.’ Whatever the monkeys are looking for, it is not fleas. ”

“ The body remains, of course, on the surface of the skin as a little reddish-orange point, scarcely perceptible unless many of them are congregated in the same position. The effect of their presence is to produce a swelling in the skin, which may be as large as a split pea, accompanied by an intense itching and a smarting which banishes sleep. ”

“ Leeches have many enemies:— water-rats, voles, the larvae of the Dytiscus beetle, the larvae of Hydrophylus, the Nepa or water-scorpion, the larvae of the dragonfly, and the adult Dytiscus—all feed upon them. Many birds also eat leeches; and it is recorded that at one artificial leech-farm, where there were 20,000 leeches, they were all eaten up in twenty-four hours by an invasion of ducks. Frogs and newts also devour them, and they are not above eating their own brothers. Aulostoma will devour its own species as readily as it will an earthworm. ”

“ At first she promenades about with the male on the surface of the human skin, but when they have paired the female begins to tunnel in the epidermis. The poor male, having been used, dies. As the mother-mite tunnels she begins to lay eggs, leaving them one by one behind her as she burrows deeper and deeper into the epidermis. Hence those that are nearer the entrance of the tunnel are always more advanced in age and development than those farther in. ”

“ This fluid plays the same part on the skin of a leech as the coelomic fluid of an earthworm, which escapes by the earthworm’s dorsal pores. There is very little doubt that both these fluids contain some bactericidal toxin which prevents epizootic protozoa and bacteria from settling on their skins. Such external parasites settle on many fresh-water crustacea—such as Cyclops, which is a floating aquarium of Ciliata. In fact, leeches, like earthworms, have a self-respecting, well-groomed external appearance. Like our dear soldiers, they are, so to speak, always clean shaven. ”

“ The habitat of the body-louse is that side of the under-clothing which is in contact with the body. The louse, which sucks the blood of its host at least twice a day, is when feeding always anchored to the inside of the under-clothing of its host by the claws of one or more of its six legs. Free lice are rarely found on the skin in western Europeans ”

“ They easily ‘scent’ their prey, and on its approach advance upon it with surprising rapidity in semicircular loops. A whole and vast colony of land-leeches is set in motion without a moment’s delay, and thus it comes about that the last of a travelling or prospecting party in a land-leech area invariably fares the worst, as these land-leeches mobilise [159] and congregate with extraordinary rapidity when once they are warned of the approach of a possible host, but not always in time to engage in numbers the advanced guard. ”

“ The moth itself is a rather insignificant, small insect, of a slatey-grey colour. Its eggs, rather irregular ovoids, are laid upon the biscuit into which the issuing larvae bore. These latter are soft and like most creatures which live in the dark, whitish, though with a tinge of pink; the head, however, is brown and hardened. The larva is constantly spinning silken webs or tissues, which in the most untidy way envelop the biscuit. It finally entombs itself in a whitish silken cocoon, and herein it ultimately turns into a chrysalis or pupa. ”

“ They certainly live twelve or fifteen years. But, if we adopt an optimistic view—and in this little book we do—the fact that they grow up so slowly and live so long shows that it will be difficult to replace the shortage of leeches in Great Britain and Ireland during the present war. This could hardly be done by home culture, for even if the war lasts three or four years we have lost the cocoons of the summer of 1914, even if we ever had them. ”

“ In fact, the three divisions into which the body of an arthropod is normally divided—head, thorax, and abdomen—are indistinguishable in mites, the body forming an unconstricted whole. As a rule, these little creatures breathe, as do insects, by tracheae, or, if these be absent, by the general surface of the body. They live for the most part on vegetable and animal juices, [90] and their mouth-parts are, as a rule, piercing and suctorial; but in some species the appendages of the mouth are capable of biting as well as piercing. The adults have typically eight legs. ”

“ How the Soldier may Guard Himself against Infestation with Lice
In times of war, when men are aggregated in large numbers and personal cleanliness—but especially an adequate change of clothing—cannot be secured, infestation with lice commonly takes place. The prevalence of lice in troops in the South African War was a source of serious trouble in that their attacks [12] caused much irritation to the skin and disturbed men’s sleep.
Lice occur chiefly on the body (Pediculus vestimenti) and head (P. capitis) . They are small greyish-white insects. The female lays about sixty eggs during two weeks ”

“ There is no courtesy in him; he does not care whether it is a king or clown whom he teases, and in every step of his swift mechanical march and in every pause of his resolute observation there is one and the same perfect expression of perfect egotism, perfect independence and self-confidence and conviction of the world having been made for flies. ”

“ In the cases which recently came under Mr. Masterman’s observation, the leeches were attached to the epiglottis, the nasal cavities, and perhaps most commonly of all to the larynx of their host. When they have been attached to the anterior part of the mouth, or any other easily accessible position, their host or their host’s friends naturally remove them, and such cases do not come to the hospital for treatment.
The effect of the presence of this leech (L. nilotica) on the human being is to produce constant small haemorrhages from the mouth or nose. ”

“ But in warm stables, restaurants, and kitchens flies are able to reproduce the whole year round. A single fly will deposit at one time 100 to 150 eggs, and in the course of her summer life may produce five, or even six, batches of ova of this size. The eggs are pearly white, elongated structures, with two converging lines, along which the egg-case will ultimately split to give exit to the larva. The eggs are laid, by means of a long ovipositor, a little way beneath the surface of the dung-heap in a position where they will not readily be dried up. ”

“ The lice are small at first; they undergo several moults and grow in size, sucking blood every few hours, and attain sexual maturity in about two weeks. The eggs will not develop unless maintained at a temperature of 22° C. or over—such as prevails in clothing worn on the human body or in the hair of the head. This is why, when clothing is worn continuously, men are more prone to become infested with lice derived from habitually unclean persons, their clothing, bedding, &c. P. capitis lives between the hair in the head, and the eggs, called ‘nits,’ are attached to the hairs. ”

“ Boiling water is also very fatal when it can be used; and recently in the poorer quarters of London the ‘flares’ which painters use in burning off paint have proved of great use in ridding matchboarding, or wainscoting, from the harbouring bugs. Passed quickly along, the flame of the ‘flare’ does not burn the wood, but it produces a temperature which is fatal to the bug and to its young and to its eggs. ”