ALGAD 127 
little fruit (Fig. 119, B and C, and Fig. 120). The spores 
it contains produce the alga plants again. 
Such a life-history is more complex than any thus far 
given. During the growing season the tetraspores multiply 
the plant; and the life-history may be indicated as follows, 
P designating the ordinary plant body: 
P—tetraspore—P—tetraspore—P—tetraspore, ete. 
Such a series, however, does not continue indefinitely; 
for it is stopped by the coming of an unfavorable period, 
such a period as winter represents to many plants. In the 
life-history of our red alga 
this unfavorable period is 
bridged by the fruit-like 
body, just as in the other 
Algee it is bridged by the 
heavy-walled odspore. Such 
Fic. 119.—One of the red Alge: A, 
sexual branches, showing antheridia 
(a), o6gonium (0) with its long neck 
(t) to which are attached two sperms Frc. 120.—A branch of one of the red 
(s); B and C, development of the Alge showing a mature fruit-like 
fruit-like body.—After Kny. body (e), with escaping spores (8). 
