148 



OF THE MOSSES AND THEIR ALLIES. 



The amphigastria are a kind of modified leaves in the 

 Hepaticse, answering in some respects to the stipules of 

 more perfect plants. Growing, as they do, on the lower 

 surface of the stem, and being very minute, considerable 

 trouble is involved in searching for them, as numerous 

 stems have to be examined ; neither are they always pre- 

 sent over the whole extent of the stem. The most likely 

 parts are healthy young shoots, especially those that sup- 

 port the reproductive organs. The eye, too, should be 

 directed to the sides of the under- surface, rather than 

 along the central axis. For the purpose of examination the 

 amphigastriae may be shaved oif with a thin and very 

 sharp penknife, or the stem itself may be divided, as 

 directed for the true leaves. The latter method has the 

 advantage of securing the stipule from injury, and of giving 

 a good insight into its mode of attachment. 



on opposite sides of the stem. In other and fewer instances they are 

 attached to, or grow from, all sides of the stem. It is of rare occur- 

 rence to find the leaves notched at the margin, but this sometimes 

 takes place. 



The cells, of which the leaves are composed, are roundish, or 

 hexagonal, from pressure, and very variable in size. This also is a 

 great assistance in the determination of species. . . . The cells 

 of the ladder scale Moss (Alicularia scalaris), for instance, contain 

 peculiar nucleate bodies of from two to four granules in. a hue in 



each of the cells (fig. 2) ; those of the three-toothed scale Moss (Pla- 

 giochila triclenticulata) fig. 3, and of the curled-leaved scale Moss 

 (Jungermaimia curvifolia), fig. 4, will illustrate some of the forms of 

 leaf cells.' ('British Hepatic^ ; an Easy Guide to the Study of,' by 

 M. C. Cooke — a work which may be consulted with advantage by the 

 student. It is crowded with figures, and its exceedingly low price 

 places it within every one's reach.) — Ed. 



