Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-26T00:47:41.693Z Has data issue: false hasContentIssue false
  • English
  • Français

Researches on the intestinal protozoa of monkeys and man

XI. The cytology and life-history of Endolimax nana

Published online by Cambridge University Press:  06 April 2009

Clifford Dobell
Clifford Dobell
Affiliation:
National Institute for Medical Research, London, N.W.3
Get access Rights & Permissions [Opens in a new window]

Extract

1. This memoir amplifies my accounts of Endolimax nana published in 1919 and 1933. The complete life-history, as observable in cultures, is now described—special attention being devoted to the nuclear structure at all stages.

2. Additional information is also given about methods of cultivation, viability of the cysts in vitro, the ‘nucleal reaction’, natural parasites (Sphaerita, etc.), and other details.

3. The life-history has been found to comprise trophic, precystic, cystic, and metacystic stages, comparable with those described in Entamoeba histolytica (1928) and E. coli (1938).

4. The trophic amoeba is redescribed, with special reference to the polymorphism of its karyosome.

5. Division of the trophic amoeba (by binary fission) has been studied, and the mitosis of its nucleus is now first described in detail. It is characterized by the formation of an intranuclear spindle, with well-developed centrioles and centrodesmus. The granular chromosomes are 10 in number, and arranged in a ring on the equatorial plate.

6. Precystic amoebae are smaller than trophic forms —the reduction in size being effected during the last two divisions before encystation.

7. The cyst is formed by a precystic amoeba in the usual way. Inside the cyst, the nucleus undergoes two successive mitotic divisions similar to those seen in trophic forms. The ripe cyst is therefore 4-micleate, though supernucleate specimens—which are viable— occur occasionally. Glycogen is normally present in young (1- and 2-nucleate) cysts, but not in those which are mature.

8. The process of excystation is described for the first time, and closely resembles that seen in E. histolytica. The entire protoplasmic contents emerge as a single 4-nucleate amoeba through a minute pore in the cyst wall.

9. Metacystic development—not previously studied —consists in simple division, by successive cytoplasmic bipartitions without division of the nuclei, into 4 uninucleate amoebulae. These grow into trophic amoebae once more.

10. The whole life-history is thus asexual, with no gametes, conjugation, or autogamy, at any stage.

Type
Research Article
Information
Parasitology , Volume 35 , Issue 3 , July 1943 , pp. 134 - 158
Copyright
Copyright © Cambridge University Press 1943

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Alexeieff, A. (1911). G.R. Soc. Biol., Paris, 70, 534.Google Scholar
Bělař, K. (1926). Ergebn. Fortschr. Zool. 6, 235.Google Scholar
Bogdanowicz, A. (1930), Z. Zellforsch. (Z. wiss. Biol. B), 10, 471.CrossRefGoogle Scholar
Brumpt, E. & Lavier, G. (1935). Ann. Parasit. 13, 439.CrossRefGoogle Scholar
Brumpt, E. & Lavier, G. (1935 a). Ann. Parasit. 13, 551.CrossRefGoogle Scholar
Cannon, H. G. (1937). Nature, Lond., 139, 549.CrossRefGoogle Scholar
Cannon, H. G. (1941). J. Roy. Micr. Soc. 61, 88.CrossRefGoogle Scholar
Chatton, E. (1910). Arch. Zool. exp. (5 sér.), 5, 267.Google Scholar
Chatton, E. & Brodsky, A. (1909). Arch. Protistenk. 17, 1.Google Scholar
Dangeard, P. A.(1886). Ann. Sci. nat. (7sér.), Bot. 4, 241.Google Scholar
Dobell, C. (1914). Arch. Protistenk. 34, 139.Google Scholar
Dobell, C. (1919). The Amoebae living in Man: a Zoological Monograph. 8°. London.Google Scholar
Dobell, C. (1927). Parasitology, 19, 288.CrossRefGoogle Scholar
Dobell, C. (1928). Parasitology, 20, 357.CrossRefGoogle Scholar
Dobell, C. (1931). Parasitology, 23, 1.CrossRefGoogle Scholar
Dobell, C. (1933). Parasitology, 25, 436.CrossRefGoogle Scholar
Dobell, C. (1936). Parasitology, 28, 541.CrossRefGoogle Scholar
Dobell, C. (1938). Parasitology, 30, 195.CrossRefGoogle Scholar
Dobell, C. (1940). Parasitology, 32, 417.CrossRefGoogle Scholar
Dobell, C. (1942). Parasitology, 34, 101.CrossRefGoogle Scholar
Dobell, C. & Jepps, M. W. (1917). Brit. med. J. 1, 607.CrossRefGoogle Scholar
Dobell, C. & Laidlaw, P. P. (1926). Parasitology, 18, 283.CrossRefGoogle Scholar
Epstein, H. (1922). Arch. russ. Protistol. 1, 46. [In Russian. German summary, p. 78.]Google Scholar
Hegner, R. (1927). Science, 65, 577.CrossRefGoogle Scholar
Jírovec, O. (1927). Arch. Protistenk. 59, 550.Google Scholar
Kirby, H. (1941). Organisms living on and in Protozoa. Protozoa in Biological Research (ed. Calkins, and Summers, ), pp. 1009–1113. 8°. New York.Google Scholar
Kudo, R. (1926). Amer. J. trop. Med. 6, 299.CrossRefGoogle Scholar
Lévitanskaïa, P. B. (1938). Bull. Biol. Méd. exp. U.R.S.S. (Moscow), 6, 403.Google Scholar
Lucas, C. L. T. (1927). Parasitology, 19, 223.CrossRefGoogle Scholar
Lwoff, A. (1925). Bull. Soc. Path. exot. 18, 18.Google Scholar
Minchin, E. A. (1912). An Introduction to the Study of the Protozoa. 8°. London.Google Scholar
Nöller, W. (1922). Die tierischen Parasiten der Haus- und Nutztiere, Bd. 1, Teil I (pp. 1–272). Berlin.Google Scholar
Pietschmann, K. (1929). Arch. Protistenk. 65, 379.Google Scholar
Reichenow, E. (1928). Arch. Protistenk. 61, 144.Google Scholar
Sanders, E. P. & Cleveland, L. R. (1930). Arch. Protistenk. 70, 267.Google Scholar
Stabler, R. M. (1932). J. Parasit. 18, 278.CrossRefGoogle Scholar
Vahlkampf, E., (1905). Arch. Protistenk. 5, 167.Google Scholar
Wasielewski, T. v. & Kühn, A. (1914). Zool. Jb., 38, 253.Google Scholar
Wermel, E. (1925). Arch. russ. Protistol. 4, 95.Google Scholar