. Des parasites animaux et la maladie humaine. Parasitologie médicale ; insectes en tant que porteurs de la maladie. Le ver de Guinée dans CYCLOPS 313 suicide. La naissance d'un Umited répétées nombre de descendants à chaque fois que le skiii de l'hôte vient en contact avec l'eau est donc le succès d'une solution à un problème qui à un ver unmeditative fouisseurs bUnd doit par ailleurs présent insuper- mesure des difficultés. Lorsque tous ses jeunes ont été déposés, en vertu de l'ulus de stim- contact avec l'eau, le ver mère shrivels et meurt et est bientôt ab- sorbés par les tissus sur lesquels elle anciennement la proie et par lequel elle parcouraient. L e

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. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. GUINEA-WORM IN CYCLOPS 313 suicide. The repeated birth of a Umited number of progeny each time the skiii of the host comes in contact with water is therefore a successful solution to a problem which to a bUnd burrowing unmeditative worm must otherwise present insuper- able difficulties. When all her young have been deposited, under the stim- ulus of contact with water, the parent worm shrivels and dies and is soon ab- sorbed by the tissues on which she formerly preyed and through which she roamed. The embryo worms, safely deposited in water, unroll themselves and be- p, ^, , 133, cydops sp. (?), some species of gin to swim about in a which serve as intermediate hosts of guinea- n , . T J. J.U worms. X about 25. fashion peculiar to them- selves. Their bodies are somewhat flattened and they have a slender tail. They swim by a few quick sculling motions of the tail, followed by a pause, then a few more strokes, etc., in the manner of a tadpole. In turbid water they remain alive for two or three weeks but eventually perish unless they come in con- tact with a Cyclops, into the body of which they make their way. They usually enter by way of the mouth, sometimes as many as six or ten entering a single Cyclops. In a day or two they leave the stomach of Cyclops and enter the body cavity. In spite of the relatively large size of the worms the crustaceans seem to feel very little inconvenience, and seldom succumb even to very heavy infection. The young guinea-worms become fully developed in Cyclops in from four to six weeks, according to the temperature, mean- while having undergone one and perhaps two moults. They are then about one mm. (^ of an inch) in length, and ready to in- fect a new host. Entrance to the new host is probably accom- plished by the accidental drinking of a Cyclops with unfiltered water. The female worms become adult in their new host in about a year so the larvae c

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