13 
(z) It may be inthe form of a disc and 
attached by its centre to the centre of the 
receptacle, the edge being free (peltate). 
(2) Asa rule it is more or less elongated 
and attached to the side of the receptacle 
(lateral), (a) either by a point or notch on one 
side, in this case it is reniform, oval or oblong ; 
or (b) by the entire length of one side when it 
is enear. Sometimes the indusium is attached 
all round the base of the receptacle and 
it is at first globose and entire enveloping 
the sorus when young, eventually opening at 
the summit and then it resembles a cup 
(calictform). 
3. Lire History ofr THE FERN 
The spores which are borne inside the 
sporangium are extremely minute bodies of a 
dark brown colour resembling the pollen grains 
of flowering plants in structure, and are like 
‘them cells consisting of the living substance, 
protoplasm, enclosed, as a rule, in a double coat 
made up of an outer exime and an inner. tntine. 
The former is provided with markings and 
elevations of various patterns. Provided with 
this double coat spores are capable of resisting 
