This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1853 Excerpt: ...necessary is to make thin longitudinal and transverse sections through the leaf. If the leaf is not very fleshy the sections are best made by the aid of the cork. In examining the epidermis of the leaves of the species Aloe and Agave, and of all other very fleshy leaves, it is necessary to detach the epidermis, ...
Read More
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1853 Excerpt: ...necessary is to make thin longitudinal and transverse sections through the leaf. If the leaf is not very fleshy the sections are best made by the aid of the cork. In examining the epidermis of the leaves of the species Aloe and Agave, and of all other very fleshy leaves, it is necessary to detach the epidermis, together with some of the subjacent cellular layers, and to place it between cork, since there is no other way in which a sufficiently thin section can be obtained. The first thing to be done is to examine the epidermis, and to ascertain whether both sides of the leaf have the same sort of epidermis, and whether or not it is furnished with stomata; the construction of the stomata themselves, as well as their mode of arrangement, may be learnt by the help of the transverse section, and by examining the detached epidermis from above. With respect to the stomata, their position and arrangement must be observed, and it must be ascertained whether they are spread over the whole surface of the epidermis or are only to be found upon certain parts of it; whether the arrangement of them is regular or irregular: and whether they are on a level with the epidermis, or raised above it, or sunk below it. The nature of the cuticle is learnt by taking very thin transverse sections and treating them with the iodized solution of chloride of zinc, or concentrated sulphuric acid, by boiling with caustic potash, or by maceration in the manner proposed by Schultz. By proceeding thus, it will be seen that that which most authors call the cuticle, embraces two things; that it consists on the outside of a structureless secretion from the epidermal cells, and on the inside of the outer layers of the epidermal cells themselves chemically altered. These two parts are generally ...
Read Less