ALLOSORUS. 
83 
called fertile. The edges of the lobes of the fertile fronds 
are rolled under (which is what gives them the contracted 
appearance), and cover the sori in the stead of a special 
indusium ; the sori when young form distinct circular 
clusters beneath this recurved margin; but as they grow, 
they join laterally (in technical language, they become 
confluent), forming two lines of fructification lengthwise 
the segments of the fronds. 
The name Allosorus is compounded from the Greek, 
and comes from alios, which means various, and sorus, 
which means a heap: the intention probably being to 
indicate the variation or change which occurs in the appa¬ 
rent arrangement of the sori, from the distinct patches to 
the continuous lines in which they are seen to be disposed, 
if examined at different stages of development—the change, 
after all, being only apparent, and not real. The name, 
however, may have been intended to express the variation 
in the character of the sorus in the different species origi¬ 
nally assigned to this genus. 
Allosorus crispus, Bernhardi. 
The Rock Brakes, or Mountain Parsley. (Plate V. fig. 1.) 
This elegant little plant, which has considerable first- 
G 2 
