20 PRINCIPLES OF BOTANY, ETC; 
§ 73: 
The Mosses have a peculiar calyx, differently form: 
ed from that of other plants, called pERICHAETIUM: 
The flowers of Mosses are so small that they cannot 
be seen without the help of a high magnifier. In 
general they are of different sexes, that is; some are 
iitirely male, others female flowers. ‘The calyx of 
the female flower remains till the fruit is ripe and 
appears at the base of the seta, (§ 21); The male. 
flower is only visible with a high magnifier; and dis- 
appears after the fructification is completed. 
In the male flowers the calyx consists of a num- 
ber of leaves, which differ from the other leaves in 
being of a finer structure, and of another form. 
The calyx of the female flower is best seen when 
the fruit is ripe, when it is observed at the base of 
the seta, fig. 140, and consists of a number of im: 
bricated leaves, which are distinguished from those 
of the Moss by their length or breadth. These 
leaves lie thick upon one another, and the whole is 
of a conical form. 
§ 74. 
The coroLxa is the envelope, or small leaves i in- 
¢losed by the calyx, surrounding the interior parts 
of the flower, and of another colour than green. It 
consists either of one piece or of several ; the first is 
called a monopetalous corolla, (corolla monopetala), 
the last polypetalous, (corolla polypetala). ‘The pieces 
it consists of are called petals, (petala). 
6 75. The 
