Nature.

Waikato Times, Volume XXIII, Issue 1926, 8 November 1884, Page 2 (Supplement)

Nature.

Two Basssercms Purn&ilcs. O.ni: of Hie nicit ihaigeroiib to health and life of all the paia&hes infescing man is the T)ochmui'> chiodenahb. This nematoiu woim \\£>^ disco\eieci by Dubini at Lilian In 183S, and thiikeu jears later Gnp^inqer made known its lelation to a disease known as tiopjcal <? uremia, &met which lime many oLj3i\ei-. \k.\g noted iis occunence in | Egypt, Bia/il, Aastiia, and in most tropical and "erni- tropical countries, throughout Northern Italy it is toloiably common. Thf para-site may be described f a follows: — The male mra3Ui.es four lines, the female fi\ lines in length , the head ia tapering and pomied, and is £lr-"«l r -"«. j d fonvtud, the mouth being diiccted toward the ventral suiface. The mouih is armed with four claw-like hooJJeta auangecJ irregularly, which conv r rqe toward iho centre of the oral cavity. The female has a pharp pointed tail ; that of the maG is blanfc, and is piovided with a ' bi-lobed, cup-like hcod, which is supported by eleven horny rayb — the median ono dividing into tv;o at its summit. The females aie much more numerous than che malea, and tLe mode of reproduction is oviporous, the larya 1 reaching maturity within the mateinal body, and being expelled alive. These lavviu are expelled in the freces, and aie believed to pass thiough their intermediate stages in dirty water, from which they axe conveyed to the inteftine of their unfortunate host by being swallowed by drinking. Once in their pioper habitat — the duodenum — they cut their way through the intestinal mucous membrane by means of their shaip hooks, and suck the blood ; here they rapidly reach matuiity. On their removal a tiny spot from which the blood oozes is left, surrounded by an aiea of congestion. The disease caused by these bloodthirsty woiras is known by the vaiious names of Egyptian chlorosis, tropical antenna, and anchyloutoma disease. The symptoms are those of progressive anremia (loss of red blood corpuscles), #Zws swelling and pain of the upper portion of ths abdomen, diarrhoea, and intestinal hemorrhages. The affection is often accompanied with a longing for strange and innutritious substances, such as chalk, clay, and wool. Tropical anaemia is usually a fatal disease, though if but few worms have been introduced into the intestine the symptoms are but slight, and life is not materially shortened. Victims of the disease may die in collapse within a few weeks or even days after the first symptoms, or may drag on a wretched existence for months or many years. Another terrible parasite is the Guinea or Medina worm (Dracunculus medinensis). It has been known from time immemorial, as there can be but little doubt of the "fiery serpents" which afflicted the Israelites being only examples of this nematoid, and Plutarch clearly icfero to it in his " Symposiacon." The Medina worm measures from one to six feet in length, and ia about one-tenth of an inch in thickness. The body is cylindrical, and terminates in a curved and pointed tail. The head is somewhat convex and flattened, and is provided with a central mouth, surrounded by four equidistant papillae. The Dracunculus produces living young, the body containing an immense number of hatched embryos held within the uterine 'ducts. The adult worm lives in the subcutaneous cellular tissue, especially that of the feet and legs, but may occur in almost any part of the body. In these situations it lies somewhat coiled, and sometimes stretched out, and Bingle individuals or sometimes many examples are found in ike same person. By the irritation caused by its presence first an abscess— accompanied. by various severe local and general symptoms — and then a consequent sinus' is formed, from

which the microscopic, sharp-tailed embryos already spoken of make their escape, never maturing in the tissues which contain the parent worm. These find their way into, sorno pool of water, and there effect an enlranco into the bodies of microscopic crustaceans belonging to the genus Cycloids. Here tbe embryos change their skins, increase in size, and complete their larval development. Should one of these crustacean bearers with its contained parasites bo swallowed with drinking water by man, the worms arrive at sexual maturity in the stomach of the latter, and here too sexual congress probably takes place. The females then make their way to the sites already mentioned, while the males probably die and are cast off in the fteces. The Guinea worm, as its name suggests, is most common in North Africa and neighboring countries ; it has, however, been found in almost all tropical lands. The attacks of this parasite are almost always accompanied with great suffering and injury to health, and even death ia by no means an infrequent occurrence. The order of the nematoid worms contains many genera dangerous lo man, besides the two examples above described, among which may be mentioned the dreaded Trichina ipimlis, and tho little less dangerous Filaria bancrofta ; the latter lives in the blood, and is the cause of a most dangeious and intractable form of chyluria and bloody urine. — Ralph W. iSehs in the Scientific Aihcrican.