Observations on the anatomy of actinia coriacea and on alcyonella stagnorum / by Thomas Pridgin Teale.

  • Teale, Thomas Pridgin, 1801?-1867.
Date:
1836
Catalogue details

Licence: Public Domain Mark

Credit: Observations on the anatomy of actinia coriacea and on alcyonella stagnorum / by Thomas Pridgin Teale. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    seiits numerous tubercular eminences, of a conical form, disposed, as has been already stated, some- what irregularly, but with a tendency to vertical and horizontal Hnes. These eminences are trans- lucent at then- circumference, and present at their summit a perforation which appears as an opaque multangular spot.* They admit of retraction to such a degree as to render the corium perfectly smooth, so that the small opaque spot alone indi- cates then' former situation; they also can be pro- truded to nearly a line in length, when they bear a close resemblance to rudimentary tentacula. The eminences on one side are often seen in the utmost degree of protrusion, whilst, on the other, they are scarcely perceptible. If, in the protruded state, they be touched with the finger, they are immediately retracted, in the same manner as the tentacula are withdrawn under similar treatment. To these emi- nences fragments of sand and shell fi^equently adhere, and the resemblance which they bear to tentacula would lead to the suspicion that it is by a power of suction, similar to that which is exerted by the tentacula, that these foreign substances are retained; the great firmness of the adhesion, however, and its continuance, in some instances, after death,f some- what militates against this idea, and suggests the possibihty that the eminences are follicular glands, whose secretion agglutinates these substances to the integument. The internal surface gives attachment * Plate 9, fig. 3. t I have a specimen preserved in spirit, in which the foreign substances adhere to the skin with great tenacity.