93 Ma. Linpsay’s Account of the 
when very young. They fhould be daily moiftened with water in . 
the moft gentle manner poffible, and the pot may be kept in a 
bafon with a little water in it. Great care is requifite to keep them 
from all forts of vermin ; covering the mouth of the pot with a net- 
work of fine brafs wire anfwered this purpofe with me.—1n about 
Io or 15 days, or perhaps later, the furface will begin to look 
green, as if fome fine mofs were beginning to grow on it: this will 
gradually increafe, and the progrefs will be nearly as I have de- 
fcribed.—W hat relates to the tranfplanting of them, after they 
have acquired a little ftrength, will eafily be judged of by every one 
accuftomed to the raifing and tranfplanting of other plants; and 
the rearing of them afterwards will be beft underftood by attending 
to the foil, fituation, and climate from which they have come. What 
. {pace of time may be required between the fowing of their feeds 
and their acquiring the leaves proper to each fpecies, I cannot rea- 
dily point out; in different forts it may be different: the fhorteft I 
have obferved has been almoft three months, fometinies more ; but 
this may be varied no doubt by various circumftances. Having 
thus given an account of the germination and progreflive growth 
of young ferns, it only remains to give fome defcription of the fruc- 
tification, which I fhall do i in a few words, Dc" by the annexed 
ee | 
EXPLANATION of Tas. 18. 
hé 1. reprefents a leaf of the Polypodium lycopodicides, and 
the dots the little clufters of fruétifications. Each clufter is genea 
rally* covered with a thin membrane or fcale, commonly called the 
+ ach, if not moft fpecies of the genus Acroftichum, and this, with feveral other 
.. fpecies of Polypodium, want this membrane or calyx. This difference therefore, Flores 
- caliculati, et non caliculati vel nudi, mo be ufeful in diftinguifhing the numerou 
fpecies of this extenfive genus. 
calyx. 
