22 , TlMEHRI. 
conditions. During the rainy season it may be found 
scattered everywhere along the sides of the trenches, 
on the brick-work of old water vats, or even on heaps of 
burnt earth by the road sides. Not being able to live 
during the dry season it comes to maturity in a month 
or two, scattering its spores everywhere, and then 
perishes as soon as the rains cease. This is apparently 
the only fern in the colony that may be called a weed, 
and it may be considered as in course of development 
to suit the altered condition of the cultivated districts. 
It is never found in the forest or on the savannahs, 
except in cases where there has been a clearing, but 
once the soil is laid bare, it may be many miles from the 
nearest cultivated ground, it comes up in profusion. 
The capability of certain plants or seeds to lie dormant 
for generations, or perhaps ages, is one of the wonders 
of vegetable life. Make a clearing in the forest, dig a 
ditch, or throw up an embankment, certain plants will 
be sure to appear that could not have been found in the 
neighbourhood before the disturbance. Terrestrial 
orchids of very rare species are commonly found in England 
on railway banks, while in Demerara the Catasetum 
discolor is plentiful only on the sandbanks thrown up 
by the charcoal burners. The question naturally arises, 
have their seeds lain dormant for ages ? There appears 
to be no limit to the vitality of seeds under favourable 
conditions. One of the most striking illustrations of 
endurance was recorded in " Science Gossip " some 
years ago. A field of turnips had been ploughed up, 
and planted as an orchard ; it remained in that condition 
for over forty years, when the fruit trees becoming old 
and almost past bearing they were grubbed up, and the 
