earth-mosses the capsule busts irregularly, or rots away and in its decay liberates the spores.
The lid or operenium varies in form, being sometimes convex, as in many of the Bryums, or conical, (1 a, 12 a,) as in Physcomitrium pyriforme, Tetraphis pellneida, &c., or it may be rostrate, (beaked) (12 a,) as in Dicranella heteromalla, &c.
When the lid is removed, or has been east off naturally, the inner structure of the capsule may be seen, and in some mosses, such as Poltia truncata, the mouth will be found to be naked, (4 c) but in many other cases it will be seen to be surrounded by a delicate fringe-like appendage, called the peristome, (12 b, 21 b) (Gr. peri around, and stoma a mouth,) This fringe consists of minute tooth-like processes, which are always some multiple of 4 in number, from 4 to 64, and the number is always constant in the species. This fringe may be either single, (124,) or double, that is there may be an outer, (20 a,) and an inner row, (20 b,) of these tooth-like processes. The teeth of the peristome vary in form and structure; in some cases, as in certain of the Weissias, they are very rudimentary; in others, as in Funaria, they are elaborately developed, and beautifully marked with transverse and longitudinal stain or markings. The teeth are often simple, (12 b,) but may be cloven, as in Dicranella heteromalla, sometimes straight, as in Didymodon rubellus, or much twisted, as in Tortula muralis, &c. In the Polytrichums the mouth of the capsule is closed by a beautifully reticulated diaphragm, to which the teeth of the peristome are attached, (21 c.) This is peculiar to the family of Polytrichaceæ, so far as British mosses are concerned.
The study of the development of mosses is one of very great interest, and worthy of the attention of all biological students. Space is too limited to allow the matter to be dealt with here in anything like fulness, and it must, therefore, refer those students who desire fuller information to that grand work of Hofmeister (Ray Society's publications) on the Germination, Development, and Fructification of the Higher Cryptogamia, pp. 129-181, where a most elaborate and exhaustive account will be found.
On the Relation of the Crust to the Interior of the Earth.[1]
By Francis D. Longe, F.G.S.
The interior of the earth is beyond the reach of direct observation, but Nature brings within our limited scope much evidence upon which a general theory may be founded as to the relation between it and the crust that the earth was once in a fluid state from. heat is an essential part of the theory of cosmogeny established by Laplace, Newton, Herschell, and others.
- ↑ Abstract of a Paper read April l8, 1878, before the Cheltenham Natural Science Society.
