396 
FERNS : BRITISH AND FOREIGN. 
can be seeD discharging from the spore-cases like 
puffs of smoke ; therefore Fern seed is said to be in- 
visible, and to have the power of rendering persons 
invisible. “ I have the receipt of Fern seed and walk 
invisible.”* Be that as it may, each particle is by the 
aid of the microscope seen to have definite forms vary- 
ing in different genera, being globose, oval, or angu- 
lar, smooth, plain, striated, or echinate, presenting 
very beautiful microscopic objects. Although these 
spores (see plate I.) are so small, they nevertheless are 
endowed with an extraordinary power of retaining 
then- vitality ; and being easily wafted by currents 
of air, readily account for the wide geographical 
range of many species of Ferns. When naturally or 
artificially placed under favourable conditions, the 
spore vegetates by expanding in the form of a simple 
oblong cell, from which other cells are successively 
produced, ultimately forming a thin green membrane, 
called the Prothallium, which lies nearly flat, and by 
the aid of fine spongioles attaches itself to the surface, 
and when arrived at full size it is of a reniform 
cordate shape, or sometimes bilobed, or obcordate, 
varying from about j to 1 inch in diameter, having 
much the appearance of a small foliaceous lichen. But 
before proceeding to describe the method of sowing 
and rearing, it is important that the seed sower should 
be made acquainted with the remarkable discovery 
made, in 1848, by Count Leszczyc Suminski, that Ferns 
possessed organs analogous to stamens and pistils of 
flowering plants, and that these were produced on the 
Prothallium. In the progress of growth peculiar cells 
* Shakespeare. 
