FERNS AND FERN ARRIES. 171 
opteris). In this genus the sterile and fertile leaves are 
totally different, the whole of the blade of the fertile leaf 
being absorbed in the fructification. It will not be many 
days now before the fern-lover may feast his eyes on the 
lively green of the sterile leaves which the sensitive fern 
sends up in every wet run and meadow-edge and swamp. 
These leaves are nearly as broad as long and are not quite 
pinnate, the divisions not extending to the mid-rib. (Fig. 
1.) The fertile leaves of this season will not yet be found, 
but those of last season will be in evidence. They are in 
the shape of a stiff, dry, flattened spike and the narrow rows 
of now empty spore-cases look like dried-up berries as they 
still cling to the short branches. (Fig. 2.) Occasionally 
there may be found, early in the season, a curious inter¬ 
mediate form. A leaf which started out to grow into a fer¬ 
tile leaf had its development arrested mid way, and the re¬ 
sult was that odd form of leaf which has gone by the absurd 
name of “variety obtusilobata.” (Fig. 3.) Of course, it 
is only an accidental abnormal product, the result of arrest¬ 
ed development. 
The sensitive fern is very abundant in our area. The 
ostrich fern, more beautiful,' perhaps, but no more interest¬ 
ing, is comparatively rare, being most frequently found in 
alluvial soil. About Manchester the extreme scarcity of 
this soil accounts for the absence, or at any rate scarcity, 
of this fern. Will any reader who discovers a station of 
this species kindly report it to Nature Study? He shall 
have due credit therefor. 
The Manchester Institute has secured the upright saw 
which was formerly used in the old saw mill on Black 
Brook. It was the gift of Mr. George A. Farmer and was 
the last “up-and-down” saw in use in Manchester. It is 
seven feet in length and is in good condition. 
