Manual of bacteriology / by Robert Muir and James Ritchie.

  • Muir, Robert, Sir, 1864-1959.
Date:
1910
Catalogue details

Licence: In copyright

Credit: Manual of bacteriology / by Robert Muir and James Ritchie. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    of iiagana. It was found that, when one of these flies was fed on a sleeping sickness patient and then allowed to bite a monkey, fi-equently trypanosomes appeared in the animal's blood, and that when fresh flies caught in the sleeping sick- ness area were placed on a monkey a similar occurrence took place. The trypanosome of sleeping sickness is 17 to 28 /x. long and 1-4 to 2 /A broad (Fig. 172); when about to divide it is both longer and broader. According to Laveran, the free part of the fiagellum often equals a fourth of the whole length, but occasionally the body protoplasm extends quite to the end of the organism. The undulating membrane is narrow, and the posterior end may be either sharp or blunt. The trypanosome contains the macro- and microuucleus characteristic of the group, and the proto- plasm often shows chromatin granules. Castellani attached great importance to a vacuole often seen in the neighbourhood of the microuucleus, but, as stated above, Laveran holds this to be an artefact. The organism divides longitudinally in the usual manner, and often two can be seen to approach each other and lie more or less side by side, but whether this indicates conjugation or not is not known. The organism does not usually long survive removal from the body, but it has been found to be motile for nineteen days when kept on rabbit-blood agar at 22° C. As we have said, when Tr. ugandense is inoculated into monkeys they often contract an illness which ultimately presents the features of tyjjical sleejjing sickness. Inoculation of other species of animals is not usually so successful, though in nearly every case, e.g. in the guinea-pig, a proliferation of the parasite, as indicated by its appearing in the blood, takes place; but often either no disease occuns or this runs a very chronic course. The relative insuscepti- bility of animals, especially of the dog, to the Tr. ugandense is taken as evidence that this organism is essentially different from Tr. Brucei. By means of microscopic examination the organisms may be found in the cerebro-spinal fluid, the blood, or the juice of glands. In the case of the first about 10 c.c. of the fluid is to be centrifugalised for fifteen minutes and the deposit placed under a cover-glass for examination ; it is better to make a little cell on a slide liy i)ainting a ring of ordinary embedding paraffin, to place the droplet of fluid in its centre, and to support the cover-glass on the paraffin ; in this way injury to the delicate structure of the organism is avoided. In fresh cerebro-spinal fluid the trypanosomes can be seen to be actively motile ; the number in which they occur varies very much, and the same is 40