146 OF THE MOSSES AND THEIR ALLIES. 



the fruit is situated at the summit of a stem, and the 

 Pleurocarpi, which bear the fruit on the sides. In one 

 word, in the first, the theca or capsule is terminal; in the 

 second it is lateral. This difference of structure necessitates 

 a difference of treatment in preparation. Bunches of the 

 lateral fruited species may be separated by the hand without 

 taking the trouble to isolate individual plants : it is better, 

 in fact, to leave them massed together, as showing their 

 character of growth more accurately. With the terminal 

 fruited species, on the contrary, the natural habit of the 

 plants is seen better if they are separated, though they 

 need not be entirely so. For this purpose, two or three 

 clean cuts maybe made with a knife through the tuft,' 

 from above downwards, thereby making thin sections held 

 together slightly at the bottom, either by the adherent 

 earth, or by their own interwoven roots. 



Some of the very delicate kinds, such as Brachyodus or 

 Seligeria, and many of the Jungermannise should be collected 

 together with the bark or stone to which they have at- 

 tached themselves. 



The Hepaticse need great care in their preparation ; not 

 the least difficulty is the getting rid of the soil from their 

 roots without injuring the leaves or breaking the stem. 

 The best method of accomplishing this' is to lay the plants, 

 just as they are brought home, in a cup of clean water, 

 then, by a gentle movement of the fluid backwards and 

 forwards, the earth will gradually separate itself and settle 

 at the bottom. The water should be constantly renewed, 

 until no signs of discoloration appear. Next let the plant 

 be carefully lifted out of the cup and laid on soft paper to 

 allow of the water draining off. Here, again, great care is 

 needed, because some of the important parts are easily 

 broken off and lost from their extreme minuteness, if any 

 roughness or over-haste is used; such are the so-called 

 gemmae, the calyx or vaginule, and the antheridia, on 

 their short pellucid footstalks. 



An ordinary lens is sufficient for the examination of the 

 stems and branchlets of the Mosses ; but the construction of 



