56 



The Naturalist. 



the objectives, and thus the objectives of all the chief makers may be 

 used with it. Its price also is another recommendation. It can be 

 purchased, with all necessary parts for the examination of mosses, for 

 £5 10s., or with polaiiscope and other additions, for £7 10s. A few 

 glass slides and thin covers, a few needles stuck into wooden handles 

 (an old soft-wood penholder will do) with the points downwards and 

 projecting about a quarter or half an inch, with the wood neatly cut 

 down at the point like a pencil— and you are fully equipped. 



Now sit down, having arranged your microscope and light, and get 

 out a single plant of the moss, with a capsule (fruit) on it. The first 

 point you have to ascertain is, does the fruit spring directly from the 

 summit of the moss, or does it spring from the side of the stem 1 In 

 the first case it belongs to the Acrocarpi (from two Greek words, 

 ahros at the top, and karpos a fruit) — or it may be pleurocarpous, that 

 is, side-fruited (from pleuron a rib, or the side, and karpos.) There is 

 also another style of fruiting, in which the capsule is terminal on a 

 short branch springing from the side of the stem. Supposing, then, 

 you have Wilson's " Bryologia," or any work based upon his classifi- 

 cation, your next point to ascertain wiU be — assuming that your moss 

 is acrocarpous — whether there be upon it a removable lid. Taking 

 it that your moss has such a lid, we will for the present pass 

 by those three genera which are not so provided, to be considered on 

 some future occasion. Having removed the lid with the point of one 

 of the needles, you must now examine the mouth of the capsule left 

 open by its removal to ascertain whether there is a fringe of teeth 

 surrounding it and springing from it, or not. Passing by those that 

 are without teeth [gymnostomi—gumnos naked, stoma a mouth), we 

 find your moss has a mouth surrounded by a number of small teeth 

 (peristome — peri around, and stoma), in one row only, i.e., peristome 

 single. You must now try to find a capsule which bears what is 

 called a calyptra (kaluptra a covering or veil). This is a thin mem- 

 branous veil at first covering the whole of the capsule, but as the stem 

 grows it splits off, and a portion of it is carried upwards on the summit 

 of the unripe capsule. Should you find one, notice whether it be 

 formed like the extinguisher of a candle, open at the bottom only — 

 i.e. mitriform — or slit up on one side, i.e. dimidiate. Finding it to be 

 dimidiate, you must now slit the capsule from base to summit on one 

 side with a sharp knife, spread it out on a slide with a little water, put 

 on a thin covering glass, and place it on the stage of the microscope 

 under a 1-inch objective, and proceed to count and examine the teeth 

 of the peristome, and their relative positions and conditions. 



(To he continmd.) 



