o98 
TERNS : BRITISH AND FOREIGN. 
ence in tlie fertility of tlie spores of tlicse two divi- 
sions is very remarkable; this is, it must be remembered, 
as found with the plants under cultivation, and as with 
many true Ferns we find, from experience, the spores 
of the latter seldom germinate in less than eighteen 
months after having been sown. On the contrary, in 
the Dcsmobrya group, many require but two or three 
weeks, and occasionally certain species of Gymno- 
gramma and Gheilanthes will germinate in as many 
days. From the irregularity, however, in this respect 
it is in a great measure governed by the state of, and 
conditions which surround, the seed ; from repeated 
trials with spores of Brained insignis, Prothallia were 
produced in forty-eight hours. Consequent on this 
irregularity, it is impossible to state what time of the 
year is most suitable for sowing to ensure success, 
especially for imported spores, which should be sown 
as soon as received, provided a proper condition can 
be given them. Therefore extra attention must be 
paid when it unfortunately occurs that the young 
Ferns are in their Prothallium stage during the winter 
season, to keep them from damping and the growth of 
conferva and musci. When it is desirable to increase any 
particular species by spores, some precaution is neces- 
sary to secure them in a proper ripe condition, and 
without spores of other species growing near being 
mixed with them. The fructified frond should be taken 
as soon as the spore-cases on the plant begin to open, 
and placed between sheets of paper in a moderately 
dry place for a few days, at the end of which time there 
will be escaped spores in abundance. These should 
be immediately sown in pots prepared in the following 
manner ; — four to six-inch pots are generally the most 
