Three memoirs on the developement and structure of the teeth and epithelium, read at the ninth annual meeting of the British Association for the Encouragement of Science, held at Birmingham in August, 1839 / by Alexander Nasmyth.
- Date:
- 1841
Licence: Public Domain Mark
Credit: Three memoirs on the developement and structure of the teeth and epithelium, read at the ninth annual meeting of the British Association for the Encouragement of Science, held at Birmingham in August, 1839 / by Alexander Nasmyth. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![removed, arfbther lamina of scales is seen on the surface of the animal’s skin. If after the death of a frog it be immersed in water, this thin external translucent layer generally separates; but upon prolonging the maceration, another lamina is found to be gradually separating from the cutis, which is dense, and sometimes measures a quarter of a line in thickness. Internally it will be found to be com- posed of very numerous cells, while externally the regular series of scales is evident. The tesselated lamina alluded to above evidently takes its origin from this layer of cuticle. An examination of the specimens which I here present to your notice, and a consideration of the facts which I have related, cannot, I think, lead to any other conclusion than that the cuticle and epithelium are organised tis- sues. It would appear that they are formed from a fluid secretion on the surface of the vascular corion. The various stages of developement being, 1, the formation of nuclei and corpuscles; 2, that of cells ; 3, the growth of the latter effected by vital imbibition ; 4, their compression and gradual conversion into minute lamellae or scales. [See PI. C. 10. Nos. 2 and 3.] In short, it appears a rational conclusion that the component parts of the cuticle and epithelium have within them- selves a power of growth; and it remains for pathologists to determine what share the derange- ment of this function has in the production of cutaneous diseases. Another argument in favour of the organic nature of the epithelium is derived](https://iiif.wellcomecollection.org/image/b21982910_0081.jp2/full/800%2C/0/default.jpg)
