Hierophant

“ Although this class contains fewer forms than the preceding some of these have within recent years been found to be of great importance because they live as parasites on man and other animals. The trypanosome whose presence in the blood and tissues of the patient causes that dreadful disease which ends in sleeping sickness belongs here as well as do several other similar kinds that produce serious troubles for various mammals and birds. ”

“ It seems that Herold was right in deriving the pupa and imago from the hypodermis (his rete mucosum) , but wrong in denying that the germs did not preëxist in the young caterpillar, and wrong in supposing that the latter originated from the blood, also in supposing that the muscles owe their origin to the fat-body. Swammerdam, and also Kirby and Spence, were correct in supposing that the imago arose from “germs” in the larva, though wrong in adopting the “emboîtement” theory. ”

“ When starved for several days the feeding of the rat fleas is conducted in a rather vigorous manner. As soon as the proboscis is buried to the full length the abdomen is raised and there ensues a gradual lateral swaying motion, increasing the altitude of the raised end of the abdomen until it assumes the perpendicular. The flea is observed at this point to gain a better foothold by advancing the fore tarsi, and then, gradually doubling back the abdomen, it turns with extreme agility, nearly touching with its dorsal side the skin of the hand upon which it is feeding. ”

“ The genital glands lie beneath, while in chilopods they lie above the intestine; this, as Korschelt and Heider state, being a more primitive relation, since in Peripatus they also lie above the digestive canal.
The nervous system of diplopods is not only remarkable for the lack of the tendency towards a fusion of the ganglia observable in insects, but for the fact that the double segments are each provided with two ganglia. The brain also is very small in proportion to the ventral cord, the nervous system being in its general appearance somewhat as in caterpillars. ”

“ The nucleus is situated in the anterior half or third of the body; the cytoplasm is very clear and free from granules. There is evidence that it is conveyed from rat to rat by the rat-louse and rat-fleas, which are now known to be its true alternative host. It is not, apparently, transmitted by the salivary glands of the insect, but multiplies in the hindgut of the flea, and, after assuming various crithidial forms, escapes in the excreta, and is thus inoculated into the wound made by the flea's proboscis. ”

“ Strophanthus constricts the muscles of the heart like digitalis, only much more violently, much more swiftly. See the contractions of the heart noted down minute after minute, until the moment of death and all—here is the irony!—so that by means of these experiments, the poison may be transformed into a medicine and the weapon of death become an agent of life—as in good hands, it has happened." Hanaud leaned back and contemplated Betty Harlowe between his half-closed eyes. ”

“ If they do not happen to possess a cauldron, they make the animal's paunch hold the flesh, and pouring in at the same time a little water, lay the bones under and light them. The bones burn beautifully; and the paunch easily contains all the flesh when it is stript from the bones, so that by this plan your ox is made to boil himself, and other victims also to do the like. When the meat is all cooked, the sacrificer offers a portion of the flesh and of the entrails, by casting it on the ground before him. ”

“ In many cases the shape of the body is so very different from the normal that the disposition of the organs of life in the interior of the body must be materially affected. In some genera, such as Andrenimorpha, the form, colour and attitude of the body and some of the limbs are plainly similar to Hymenoptera. These Insects have a highly-developed frenulum, retinaculum, and proboscis; bipectinate antennae in the male, a complex organ at the base of the abdomen on each side, and are in fact highly-developed forms, except perhaps as regards the structures in connexion with flight. ”

“ The rat-tail maggots or larvæ of Helophilus are parasitic. Two or three instances have been recorded from the horse. I possess one from the human intestine. Kirby also quotes an instance in which Heloph. pendulus was obtained from the stomach of a woman (‘Philos. Mag.,’ vol. ix, p. 366) .
A vast number of non-parasitic insects are injurious to man and beast. Inasmuch as they subsist at the expense of their victims and also adhere to his person during their attacks for a shorter or longer time, they, like the leeches, may be spoken of as free parasites. ”

“ Such insects as dragon-flies and may-flies, whose young, though unlike the parent, develop into the adult form without a resting pupal stage are said to undergo an “incomplete transformation” or to be hemimetabolic. The absence of the pupal stage depends upon the fact that in the ametabolic and hemimetabolic Hexapoda the wing-rudiments appear as lateral outgrowths (fig. 22) of the two hinder thoracic segments and are visible externally throughout the life-history, becoming larger after each moult or casting of the cuticle. ”

“ We have already seen some of the wonderfully curative properties of animals—let us learn something of their own medical attainments—as described by Pliny. “The hippopotamus has even been our instructor in one of the operations of medicine. When the animal has become too bulky, by continued overfeeding, it goes down to the banks of the river, and examines the reeds which have been newly cut; as soon as it has found a stump that is very sharp, it presses its body against it, and so wounds one of the veins in the thigh ”

“ The horse-flies have been definitely convicted of transferring the trypanosome of surra from diseased to healthy animals and there is good evidence that they transfer anthrax. The possibility of their being important agents in the conveyal of human diseases should not be overlooked. Indeed, Leiper has recently determined that a species of Chrysops transfers the blood parasite Filaria diurna. ”

“ CASE III. Herophon was seized with an acute fever; alvine discharges at first were scanty, and attended with tenesmus; but afterwards they were passed of a thin, bilious character, and frequent; there was no sleep; urine black, and thin. On the fifth, in the morning, deafness; all the symptoms exacerbated; spleen swollen; distention of the hypochondrium; alvine discharges scanty, and black; he became delirious. On the sixth, delirious; at night, sweating, coldness; the delirium continued. ”

“ Since Glossina palpalis acts as an essential host of the parasite and the chief, if not the only, transmitter, the fight against sleeping sickness, like that against malaria and yellow fever, becomes primarily a problem in economic entomology. The minutest detail of the life-history, biology, and habits of the fly, and of its parasites and other natural enemies becomes of importance in attempts to eradicate the disease. ”

“ But in many highly organized insects a remarkable concentration of the trunk-ganglia takes place, all the nerve-centres of the thorax and abdomen in the chafers and in the Hemiptera, for instance, being represented by a single mass situated in the thorax. The legs, wings and other organs of the trunk receive their nerves from the thoracic and abdominal ganglia, and the fusion of several pairs of these ganglia may be regarded as corresponding to a centralization of individuality. ”

“ In examining the alimentary tracts of insects for possible flagellate stages of Leishmania, it must be remembered that in many insects natural flagellate parasites, belonging to the genus Herpetomonas, may occur therein; such natural insect flagellates may be harmless, and have no connection with the life-cycle of L. donovani. Natural herpetomonads are known to occur in the alimentary tracts of flies, mosquitoes, sand-flies, fleas and lice, but not in bed-bugs. ”

“ Feeding experiments with blood-sucking insects in the case of these Herpetomonads are very difficult and tedious, owing to the fact that unless a very good case is selected it is almost impossible to follow one or two developing parasites in the guts of blood-sucking insects. Further, such experiments must be carried out with great precision, and the observer must possess a good working knowledge of the many harmless gut flagellates which occur in nearly every insect. ”

“ By day it serves him to catch fish, while at night he spreads it over the bed in which he is to rest, and creeping in, goes to sleep underneath. The gnats, which, if he rolls himself up in his dress or in a piece of muslin, are sure to bite through the covering, do not so much as attempt to pass the net. ”

“ The unsuspecting animal, taking his usual evening stroll, strikes his foot against the rope, which dislodging the stakes, the harpoon comes thundering down and the Hippopotamus is transfixed, to be found in the morning by the trapper, probably dead or dying, a long way from the scene of the trap. ”

“ He then cut out from each side of the head, close to the root of the fangs, the venom-bags.
“You see that, to enable the head to contain these bags, it is very much broader than that of the harmless snake,” he observed. “We shall find the same breadth of head in all the venomous species. The bags contain between them about eight drops of poison, one of which would be sufficient, introduced into the blood, to kill a man or a horse. You see round the base of each fang, a mass of muscular tissue. ”

“ Van Keulen found a virulent insect bite—dark red, with a purple ring around it—which suggested a tsetse-fly or something less innocuous. An examination indicated that death must be due to heart-failure induced by sheer fright rather than to the bite—though a subsequent autopsy indicated that the germ of trypanosomiasis had been introduced into the system. ”

“ As regards the perfection of the senses, where, as in dragon-flies, the eyes are very large, the optic ganglia are correspondingly so, and in the same insects the antennæ being very small, the antennal lobes are almost rudimentary. The ants exhibit inverse conditions; in their brain the antennal lobes are well developed, while the optic ganglia are reduced, and where, as in Typhlopone, the eyes are wanting, they are completely atrophied.
Fig. 256.—Head of Anophthalmus tellkampfii, showing the brain,—the optic ganglia, nerves, and eyes totally atrophied. ”

“ It may in this connection be observed that some authors derive the book-lungs or book-leaf tracheæ of Arachnida from the gills of Limulus; hence if those of Arachnida arose from quite different and more specialized organs than dermal glands, it is not impossible that the tracheæ of Peripatus, Myriopods, and insects arose de novo, and then we need not look for any primitive structures in worms from which they arose. ”

“ Certain other Acanthopterygii are capable of inflicting wounds, but, although fishermen often believe them to be venomous, or such properties are frequently attributed to them in stories, it is doubtful whether they possess poison-glands. The accidents produced by them are due rather to the fact that the spines in their fins are extremely sharp, and that their flesh is toxic. ”

“ Most of them live in the sea, but some in fresh water and moist earth. In their internal structure they approach the Turbellaria on the one hand and the higher Vermalia (especially the Enteropneusta) on the other. They have a good deal of interest as the lowest and oldest of all animals with blood. In them we find blood-vessels for the first time, distributing real blood through the body. The blood is red, and the red colouring-matter is haemoglobin, connected with elliptic discoid blood-cells, as in the Vertebrates. ”

“ A poison that produces death by totally different means than paralysis, may yet cause in nerves a complete deadness to stimuli.
Experiment XI.
The right thigh of a frog (Rana tigrina) was tightly ligatured, so as to completely prevent circulation through the limb, the nerve being included. One cubic centimetre of a solution of strychnia, containing two centigrammes of strychnia, was injected into its dorsal sac. ”

“ The Heloderm has a round, heavy tail, of no service to it in swimming, and short, weak fingers, ill suited to climbing; and it passes its lethargic existence on the sandy plains of Mexico, manifesting in its actions, or rather in its inactivity and stealthiness, a conscious timidity and cowardice. Motionless for hours, with an impulse to retreat if molested, but attempting to bite if angered, its noxious saliva would seem to be rather protective than aggressive. It may have formidable enemies at home; and by all we see of it here, it does not use its teeth as a means of obtaining food. ”

“ In its slow, stealthy movements there is the same striking contrast between the Heloderm and most other lizards, that there is between the deadly vipers and the active colubrine snakes; and the inquiry suggests itself, Can the venom elaborated in their system so act upon themselves as to produce this habitual lethargy? Drowsiness and coma are almost invariable effects of snake venom in the blood, and why is it that the deadly serpents are so constitutionally different from others? ”