88 



The Naturalist. 



because you can count thirty-two points, but if you look carefully you 

 will see that there are really only sixteen teeth, and that each is biiid 

 or split nearly down to the base, and that they are placed at equal 

 distances from one another, forming a regular series round the mouth. 

 You mil further observe, that across these teeth, or rather across the 

 segments of each tooth below, are a number of transverse bars, in part 

 joining the segments together, and called trabeculse, (from trdbs^ a beam, 

 trahecula, a little beam) ; and that each tooth is composed of two layers? 

 one, the outside, of deep lake or crimson colour, the other, the internal 

 one yellow, and that the yellow one projects on either side beyond the 

 red one, being the wider of the two. If this capsule be ripe or nearly so, 

 and it should be, to be properly examined, you may find that your vision 

 of it is much obscured and hindered by a great number of little dot- 

 like bodies floating about it in the water on the slide. These are the 

 spores, of which more hereafter ; at present they are in your way, and 

 must be got rid of. This may be done by gently washing them away 

 with a wet camel's hair brush, and then placing the capsule on another 

 clean slide with water. 



If now you examine another capsule with a good hand magnifier, 

 you will find that its general shape is cylindrical, that it stands nearly 

 upright from the stem which supports it, called the seta {seta, a hair or 

 bristle), or sometimes you will find it a little inclined from the perpen- 

 dicular. This is a character found in many capsules of other 

 genera, but note particularly that on one side, near the base, there is a 

 little protuberance, caUed a struma, hence it is said to be strumose 

 {struma, a swelling in the neck, a wen,) and that there are a 

 number of lines or low ridges running from the apex to the base ; it 

 is thus what is called striated {stria, a ridge). 



Having made yourselves so far master of the structure of the gener- 

 ative organs of your moss, turn to the analytical key at the beginning 

 of Wilson's Bryologia, or my Synopsis, which is nearly, but not quite 

 the same. You find your moss is acrocarpous, of division B, capsule 

 with a deciduous lid : Sect. II, peristome single : Sub-div. II, calyptra 

 dimidiate : b. calyptra not inflexed at the base : * * * teeth 16, deeply 

 bifid, equidistant : J J J capsule cernuous or inclined, unequal ; and on 

 reading over the first generic diagnoses under this section, you wiU 

 find your moss is of the genus Ceratodon (see p. 11, Hobk. Syn.) You 

 have now attained the first step in your examining process, and should, 

 on having reached this point, have gained some considerable insight 

 into the structure of mosses generally ; at the same time, the method 

 you have been pursuing is, in its main features, a purely artificial 



