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

  • William Aitcheson Haswell
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.

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    covered with spinules; and a similar case had previously been observed by Pintner. The early separation of the proglottides in this and other species is obviously correlated with the free locomotive habits of the strobila. With a much longer train of connected proglottides, the posterior loaded with eggs, such movements would be rendered difficult or impossible. The spiral valve in the intestine of the Elasmobranch renders it possible for the separated proglottides, without definite organs of adhesion, yet with an adaptation for creeping movement, to remain within their host until such time as the uterus has become fully charged with eggs. This Cestode is to be referred to the genus Phylloboth- rium of P. J. van Beneden. In the definition given by that author^ the bothridia are described as notched externally, but the notch is not present in one of van Beneden^s own species (P. auricula), and cannot be looked upon as of generic importance. I propose the name of P. vagans for the Cestracion parasite, which appears to be distinct from all the species described hitherto.” The only species of Phyllobothrium, of the structure of which a detailed account has been published, are P. thridax and P. D o h r n i i. These have both been pretty fully described by Zschokke (20, p. 327 et seq.) ; but, as mature segments were not met with by that author, many features of import- ance, more particularly in the reproductive apparatus, were overlooked. Integument and Nervous System. The cuticle (fig. 4, cu.) is homogeneous and not divided into layers. Immediately beneath it are the usual external longi- tudinal [e. 1. m.) and circular (e. c. on.) layers of muscular fibres. The subcuticular cellular layer is much better developed in the strobila than in the free proglottides, in 1 1, p. 120, and 2, p. 123. 2 I have not seen the original description of P. gracile, Wedl., from Torpedo mar mo rat a, but only tlie brief definition given by Lonnberg (11).
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