spores. 
35 
as to the length of time they take to germinate — 
from a few days to many months. Nothing, there- 
fore, can be said in respect thereof, as even indi- 
vidual spores from the same frond show considerable 
variation. Similarly, although Fern seedlings, 
when under suitable conditions, grow quickly during 
the spring and summer, it is impossible to state how 
long they will take to form little plants. Seedlings 
of Adiantura, Pteris, Gy vino gramme, N e^jlirodium, 
&c., soon make little subjects requiring to be 
potted singly; whereas those of others, especially 
Gleichenia (Fig. 26) and Marattia, grow so slowly 
that their first fronds are not formed until the third 
year after the sowing. 
There is another important reason why Ferns, 
whenever practicable, should be propagated from 
spores — the chance of obtaining some variation from 
the type worthy of perpetuating. To such we owe 
the brilliantly-coloured Adiantiim rhodophylhcm 
(which was produced from a batch of seedlings of 
A. Victorice, itself a freak of nature or a natural 
hybrid, found amongst a quantity of A. Gliieshreghtii 
{scutum) seedlings) and many another elegant 
Maidenhair; IS eylivole/pis Bausei, a seedling from 
N. phcm a, from which it differs considerably, and 
on which it may be considered a very decided im- 
provement, being, in fact, a delicately plumose 
form; Davallia elcgans polydactyla and D. 
M ariesii cristata ; Gy m ii a gram m e sch izo phylla 
gloriosa; and endless varieties of Pterin, but none so 
striking as P. treinvla grandiccps . 
Here it may be well to observe that on account of 
the minute nature of the phenomena observable in 
fertilisation ir. Ferns, systematic hybridisation 
as practised with plants provided with flowers, and 
consequently with visible organs, is impracticable. 
Still the fact remains that by sowing the spores of 
several varieties together offspring of mixed char- 
acteristics are produced, thus proving that crossing 
really takes place. In several of the cases of garden 
h3^brids, for instance, none of which are known for 
certain to be the result of forethought, a connection 
D 
