BRITTLE FERN. 79 
lanceolate and pinnate; the pinne are also pinnate ; 
but beyond this they appear to possess no character in 
common. The length of the stalk is also very various. 
The lateral veins are alternate, and each is usually 
divided into three or four branches, one extending to 
every serrature in each lobe of the pinnule. Almost 
membranous involucre attached on one side only 
beneath the capsules; its margin, at the farthest 
extremity from its attachment, is striated, and 
split into capillary segments, or sometimes 
torn in a ragged manner, and at length entirely dis- 
appears: the clusters of seed rapidly increase in size, 
frequently becoming confluent. In cultivation I have 
observed that sometimes, from the plant receiving a 
check from exposure or improper treatment, the clusters 
_ This pretty and fragile but hardy species has a very 
extended geographical range in the temperate regions 
of E 
urrey, Kent, Essex, Suffolk and Norfolk: in Devon- 
