THE PRINCIPLES OF BOTANY. 
617 
group, has a vernation which has been described as involute 
— that is, the frond, or the members of a compounded frond, 
are rolled inwards before expansion, and hence the frond of a 
young fern presents an appearance somewhat resembling a 
crosier or shepherd’s crook. 
The thecse, or cases containing the sporules, are highly 
interesting, both in an anatomical and physiological view, 
and as we consider Prof. Lindley’s view of their difficult 
morphology deserving of the greatest attention, we make no 
excuse for quoting it. 
“The thecae of ferns may be considered minute leaves 
having the same gyrate mode of development as the ordinary 
leaves of the tribe ; their stalk the petiole, the annulus the 
midrib, and the thecae itself the lamina, the edges of which 
are united.” 
As regards these thecae it will be well to point out that on 
putting a cluster of the so-called seeds from the dorsum of 
the common male-fern Aspidium Filix-mas these organs 
may be seen simulating small sacks, which contain the spores, 
along the dorsum of which is a highly elastic cellular spring ; 
this extending, bursts the sack and frees the sporules. 
It is worthy of remark that ferns produce an immense 
quantity of sporules, which is doubtless a wise provision of 
nature for the continuance of the species, for when we see 
that each species has its own chosen locality in some particu- 
lar soil or some peculiar position, these plants would soon 
become extinct but for a large superabundance of the repro- 
ductive element. 
Ferns are great favorites with the lover of plants, and 
will ever form an admired portion of the herbarium of the 
collection botanist ; hut perhaps for their grandeur and variety 
few plants are less esteemed for their economic or medicinal 
qualities. 
The beautiful maidenhair is used by the French in the 
preparation of the Strop de capillaire , which Pereira tells us 
is “ prepared by adding sugar and orange flower-water to an 
infusion of maidenhair, which when diluted with water forms 
a refreshing drink.” 
One of our commonest species — the Aspidium Filix-mas — 
was esteemed by the older Greek and Latin physicians. 
Pereira says, “ It is only employed as an anthelmintic ; 
Theophrastus, Dioscorides, Pliny, and Galen used it as such. 
The attention of modern practitioners has been directed to it 
principally from the circumstance of its being one of the 
remedies employed by Madame Nouffer, the widow of the 
Swiss surgeon who sold her secret method of expelling tape- 
