GUINEA-PIG 



GUINEA-WORM 



457 



Hold liy druggists under the name (uiim-a Pepper; 

 \\hil*t" the name* Guinea I'epjRT, Maleguett* 

 IVpper, ami Ethiopian 1'eiiper ha\e IM-.-M applied 

 t<> tin- ilried fruit of Ciibcwt Clitrii (see CUBKBS), 

 ami t.i i In- seeds of llnt>zrli<i(or Xylopta)JtMoptoa t 

 : nl) of tin- natural order Anonacew. Up to the 

 d.e of the IHth century Guinea I 'upper continued 

 in request, when the peppers of the East drove it 

 from the market. 



(iililH'n-piif. or CAW ( Cavia ), a genus of small 

 South American rodent*, widely represented in 

 Britain hy the familiar domesticated species. The 

 k'eiius, comprising nine sj)eeies, is typical of the 

 family Caviiila- (included in the porcupine-like sec- 

 tion of Uodenta), and is nearly related to the largest 

 niemher of the order the Capyhara or Hydro- 

 chirrus. The guinea-pigs have short limbs, the 

 fore feet hearing four toes, the hind-feet only three ; 

 the fore- feet are not webbed; the upper lip is not 

 cleft, the ears are short and roundea, and the tails 

 are wanting. The Common Guinea-pig or Cavy 

 (('. i;,/,ni/n ) whose name Guinea is believed to 

 be a corruption of Guiana was introduced into 

 Knrope from South America in the 16th century. 

 Its supposed wild original, the Restless Cavy (C. 

 aperea), abounds on the banks of the La Plata, 



Guinea-pig. 



and is found in Bolivia and Brazil. Its colour is 

 dark brown on the back and yellowish-gray under- 

 neath. It lives in small troops near the borders of 

 forests, whence it emerges at dusk and on gloomy 

 days in search of food. It is timid and stupid, and 

 falls an easy prey to carnivores and serpents. The 

 common guinea-pig resembles it closely in nearly 

 all points except colour, which is very variable, as 

 in other domesticated animals. The guinea-pig 

 multiplies with great rapidity, and may begin to 

 bear young when two months old, producing one 

 to four at a birth, five or six times a year. The 

 other species occur from the Strait of Magellan to 

 Bra/il, and one is found in Peru. Although now 

 exclusively South American, fossil forms are said 

 to have been found in the Miocene deposits of 

 S \vitxerliunl and France. Some species of Cavia 

 are shot for food, but no such use is made of the 

 domesticated form. 



Guinea- worm, known also as Filaria Medi- 

 nensis, or /'. Dntcitncvlus, is a parasitic animal 

 that seems to have been known from the earliest 

 times. Plutarch quotes a passage from a still 

 earlier author which seems clearly to refer to 

 this worm. But our knowledge of its natural 

 history is still very deficient, and we are at present 

 only acquainted with the female. The body of this 

 animal is slender, cylindrical, and somewhat com- 

 pressed, and is of the thickness of pack-thread, 

 except at the posterior extremity, where it is some- 

 what attenuated. It is opaque, of a milk-white 

 colour ; on each side there is a longitudinal line ; 

 and when examined by the microscope it is seen to 

 be marked with numerous transverse striie. The 

 anterior extremity is obtuse and the mouth circu- 

 lar and beset with, four acute spines. The length 

 of the worm varies from less than half a foot to 



parent; B, the same un- 

 coiled in a drop of water : 

 a, the head ; o, the com- 

 mencement of the tail and 

 the anus. 



three yards. On examining an adult specimen, 

 extracted by Malgaigne in Paris in 1854, Robin 

 found no trace of intewtine, 

 or of any organ except a 

 very thin sheath (a nt- m- 

 or oviduct), which was 

 filled with young animals 

 rolled up in coils, with the 

 tail occasionally project- 

 ing outwards (see A in the 

 figure). In these young 

 animals we can trace the 

 course of the intestinal 

 canal, which apparently 

 becomes subsequently ob- 

 literated by the excessive 

 development of the genera- 

 tive organs and the eggs. 



This worm is indigenous 

 only in certain hot coun- 

 tries, and its geographical 

 distribution is regulated by 

 laws into which we have 

 no insight, save that heat 

 and moisture are necessary 

 for its production. Among 

 places as especially noto- 

 nous for its occurrence are Young Filaria Medinen 

 Senegal, Gaboon, the banks (magnified) : 



of the Ganges, Bombay, A, individual coiled up, as 

 the peninsula of India, *" in "> bly of 

 Persia, Arabia Petrsea, the 

 south coast of the Red 

 Sea, the region round the 

 Caspian Sea, Upper Egypt, 

 Abyssinia, certain districts 



of Nubia, the swampy regions of the White Nile, 

 and Guinea. It has been introduced into certain 

 parts of America by negro slaves. The disorder 

 occasioned by these worms frequently becomes an 

 epidemic in years of heavy rain, and esj>ecially in 

 marshy districts. It appears also to be connected 

 with the season, being especially prevalent in the 

 East Indies during the rainy season, and in Upper 

 Egypt shortly after the regular inundation of the 

 Nile. 



The mode of production of this parasite in the 

 human body is not known with certainty. The 

 probability is that the young animals while still 

 very minute penetrate the skin, although by what 

 mechanism tney can effect their lodgment we 

 do not know. Having gained an entrance into 

 the body, the guinea-worm takes a considerable 

 time to develop. This period varies from two 

 months to a year or even two years. The presence 

 of the worm often produces no annoyance for a 

 considerable time alter it has been detected ; at 

 other times it gives rise to emaciation, and possibly 

 even death from exhaustion. As a general rule 

 the vesicles caused by the inflammation excited 

 by the presence of the worm open spontaneously 

 in a few days, and two or tnree inches of the 

 anterior end of the animal come forth. This end 

 is gently pulled, and coiled round a little roll of 

 linen or a small stick, and this is fastened over the 

 wound with sticking-plaster and a compress. The 

 extraction is repeated twice a day by rotating the 

 substance round which the worm is twisted, and 

 the operation is often not completed in less than 

 two, three, or more months. From the most 

 ancient times the tearing of the worm has been 

 regarded as a very dangerous accident. It un- 

 doubtedly gives rise to violent swelling, fever, 

 sleeplessness ; and shortening and deformities of 

 the legs, lingering fistula, mortification, and death 

 (sometimes even sudden death) must be reckoned 

 amongst the notable consequences of breaking 

 the worm. See Quain's Dictionary of Medicine - 



