The metamorphosis of Filaria sanguinis hominis in the mosquito / By Patrick Manson.

  • Manson, Patrick, Sir, 1844-1922.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: The metamorphosis of Filaria sanguinis hominis in the mosquito / By Patrick Manson. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    canal and other organs, and enhanced muscular power; then eat or bore its way through the integuments of the dying mosquito, and finally obtain liberty in the water into which the insect has fallen. It is impossible to do this ; but, by comparison of a large number of dissections, we can follow the history of the animal in the mosquito almost as perfectly as if we had watched in transparent tissues the progress of a single individual from the human body to the water. The experimentum crucis of this theory, as I have already said, I have not had the hardihood to attempt. But from what I have written, any one anxious to make it will have no difficulty in gathering what is likely to be the most successful method. Were I to attempt it I would pr6ceed in this fashion:—I would feed my mosquitoes on a filarious subject, I would collect them every morning, giving each a bottle to itself. Those that survived to the afternoon of the seventh day I would transfer to test-tubes; these I would invert over a watch-glass, containing a little water. When the insect died I would allow it to remain on the water a few hours and then remove it. The water it had fallen into, and which probably now contains the Filaria, I would transfer to a stock-bottle contain- ing water. This process I would repeat for several days. I would then administer portions of the contents of the stock-bottle to the subject of the experiment. I would continue this for a month, every day adding fresh mosquito-water to the stock-bottle, and every day administering a draught of its contents. After a time I would commence the examination at night of the finger-blood. I am quite satisfied as to what would be the result. EXPLANATION OP PLATE XXXIX. [All the figures with the exception of figs. 10, 34, 35, 37, 43, 44, 45, and 46, are magnified about 188 diameters.] Fig. 1. The embryo Filaria sanguinis hominis as it appears in the blood, or lymph, or in the abdomen of the mosquito immediately after ingestion, gL x j-^-0 Fig. 2. A Filaria about an hour after ingestion by the mosquito. The sheath has been cast, transverse striation and oval pouting are very distinct, and the animal is indulging in the snake-like wriggling by which it moves from the abdomen to the thoracic viscera. In the mosquito from which this specimen was obtained many Filaria were found in the newly ingested blood in the insect's abdomen. All were active and transversely striated. Most had cast the sheath. In one the sheath was lying at some distance, in another it trailed after the animal, while in a third it lay across it. Oral pouting was distinct in all; but no double outline, or further struc- ture, could be detected in any of them. In the same insect two Filarice were found in the thorax; they were structureless, without sheath, somewhat swollen from endosmosis, an obscure convoluted granular-looking condensation occupying most of the body. Fig. 3. From the thorax twelve hours after ingestion, J/ x ^jfeJ'. The abdomen of the insect was half filled with blood, in which moved many active, trans- versely striated, pouting Filaria. They had no sheath. In the thorax many were found. SECOND SERIES.—ZOOLOGY, VOL. II. 56