Physiological and pathological researches / being a reprint of the principal scientific writings of the late T. R. Lewis ... Arranged and edited by Sir William Aitken ... G. E. Dobson ... and A. E. Brown.

  • Lewis, T. R. (Timothy Richards), 1841-1886.
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: Physiological and pathological researches / being a reprint of the principal scientific writings of the late T. R. Lewis ... Arranged and edited by Sir William Aitken ... G. E. Dobson ... and A. E. Brown. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    820/920 (page 638)
    For some time I was inclined to think that they might be the spermatozoa of some parasite hidden in the tissues of the animal, a view which strongly forced itself upon me some years ago, in 1878, by having accidentally observed a large number of spermatozoids escaping from the reproductive pore of a fragment of taenia which I had found while dissecting a rat. The head of the taenia was not found, so that the entozoon could not be identified with certainty, but it probably was a portion of Taenia microstoma or some closely allied species. My notes run as follows:— The segments having been placed on a slide spermatozoids are seen to escape from the genital pore of nearly every one of them. For a few moments after their escape they presented, with amazing exactness, the characters of the spirillar organisms found in the blood of rats, but which were not present in the blood of this particular specimen. It seemed, however, that the water in which the taenia segments were mounted and into which they escaped was not suitable to their preservation. They rapidly underwent changes of form, and almost before half a dozen of them could be sketched disintegrative changes set in, and the previously active flagellated organisms were transformed into quiescent, filamentous shreds. It has not been considered necessary to reproduce the sketches of them which were made, seeing that both as to size and form they are so very like several of the figures in the woodcuts already given. The organisms found in the blood of rats, however, are by no means so sensitive to the action of water as this. Leuckart, in his recently published review of the additions which have been made during 1876 to 1879 to the literature of low forms of animal life,* suggests that it is doubtful whether these rat organisms should not be relegated to the class of organisms described by Dr. Gaule as being present in the blood and spleen of frogs and termed by him Cytozoa rather than to the Flagellata. Readers will recollect that Dr. Gaule was under the impression that these Cytozoa (also described by him as Wiirmchen ) were the result of certain changes which took place in the blood-corpuscles and other cellular elements of frogs. Professor Ray Lankester, however, in the number of the Quarterly Journal of Microscopical Science for January, 1882, has shown that such an inference is wholly erroneous, and has, I think, very satisfactorily demonstrated that Gaule's Cytozoa are independent parasitic organisms —that they represent, in fact, the young stage of a Sporozoon. It is not quite clear to which view of the nature of these Cytozoa, to Gaule's or to Lankester's, Leuckart refers in the paragraph above cited. In his recently completed Manual of the Infusoria, Mr. Saville Kent, on the other hand, has placed the blood-organism of the rat amongst the Flagellata, and has named them Herpetomonas I^ewisi; at the same time he points out that it is possible that further research may possibly demonstrate their identity with the discharged spermatic elements of the minute nematodes, micro-filariaj, or other metazoic endo-parasitic forms known to flourish amid the same surroundings. * Bericht uber die wiesenschaftlichen Leistungen in der Naturgeschichte der niederen Thiere, II Halfte 1883, p. 775.