On a Cestode from Cestracion / by William A. Haswell.

  • Haswell, William A. (William Aitcheson), 1854-1925.
Date:
[1902]
Catalogue details

Licence: In copyright

Credit: On a Cestode from Cestracion / by William A. Haswell. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    1/24
    ON ft. On a By William A. Haswell, M.A., D.Sc., F.R.S., Professor of Biology, University of Sydney. With Plates 22—24. General Features. The Cestode, the results of a study of which are embodied in the present paper, occurs, usually in abundance, in the large intestine of the Port Jackson shark. It is one of these re- markable forms to which attention appears to have been first specially directed by P. J. van Beneden (1 and 2), in which the proglottides are set free from the posterior end of the strobila long before full maturity has been reached, and only attain a stage corresponding to that of the ‘‘ ripe proglot- tides of a Taenia after having pursued an independent existence for some considerable time. The strobila is actively locomotive, and appears to use the suckers more in connection with progression than as organs of permanent attachment. It is only 9 or 10 cm. long in the preserved condition. There is an elongated neck-region with a breadth, in the preserved specimens, of half a millimetre. The four sessile bothridia (fig. 1) are somewhat spoon-shaped, the anterior end being the narrower. The margin of the bothridium is very prominent, finely crenulate, and in the living condition extremely extensile, so that the shape is undergoing constant modification. In preserved specimens VOL. 46, PART 3.—NEW SERIES. B B