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Pearl undertakes astudy of variation and correlation in conjugating and non-conjugating specimens of the common ciliate infusorian, Paramecium caudatum, for the purpose of obtaining answers to the following questions: Is the portion of the Paramecium population which is in a state of conjugation at a given time differentiated in respect of type or variability or both from the non-conjugating portion of the population living in the same culture at the same time? Is there any tendency for like to pair with like ('homogamy') in the conjugation of Paramecium, and if so, how strong is this tendency? The material on which this paper is based is comprised in eight series, taken from three different cultures at different times, and includes altogether the measurements of 1894 individual Paramecia. The characters studied are length and greatest breadth of the body, length-breadth index, and the difference in length between the two individuals of a pair of conjugants. In the measuring conjugant pairs are taken at random, and then in each case the two undistorted non-conjugant individuals which are lying nearest in the field of view of the microscope to the conjugant pair are measured. This procedure is followed to avoid any subconscious bias in choosing non-conjugants.

Subject: Biology / Biostatistics

Received 15 November 1905. Read 7 December 1905. Communicated by Karl Pearson.

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 77 of the Proceedings of the Royal Society B as 'A biometrical study of conjugation in paraœmcium'.

A version of this paper was published by Pearl in Biometrika: Pearl, Raymond. 'A Biometrical Study of Conjugation in Paramecium.' Biometrika, volume 5, number 3 (1907), pp. 213-297.

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Raymond Pearl

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Raymond Pearl, Unpublished paper, 'A biometrical study of conjugation in Paramaecium [Paramecium]' by Raymond Pearl, 1905, AP/77/2, The Royal Society Archives, London,, accessed on 20 July 2024

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