PE CULIARITIES. 
7 
tribe Aspidiece. If there is no apparent indusium (it being minute or 
on the under side of the fruit-dot), and the fruit-dot is on the back of 
the vein (so that it conceals the vein), not on the end, it belongs to the 
same tribe. If the fruit-dots are longer than broad, and are either straight 
or horse-shoe shaped, are situated on the upper side of the veins (so that 
the veins are not concealed by them), and are covered by an indusium 
which is closed on the side next the vein and -open on the other, so 
forming a little pocket, it is a spleenwort. If the fruit-dots are rather or 
very long, parallel to the midrib, and provided with an indusium like 
the spleenworts and situated on the side of the veins, it belongs to the 
tribe Blechnece. If there appears to be no distinct fruit-dot nor indusium, 
but the spores are concealed along the incurved edge of the frond (at 
least when the frond is young), it belongs to the tribe PteridecE. But i, 
the spores occur along the edge of the frond, and it is not curved over 
them (at least when young) and there is no indusium, or if the spores 
arise in narrow lines along the veins and are devoid of an indusium, it 
belongs to the tribe GrammitidecB. If, however, it does not belong to 
any of these, and if the frond is pinnate and the two lower pinnae are 
long stalked and bear all the fruit, the upper part of the frond being 
sterile, it is an Aneimia. In case this test fails, it must belong to an 
entirely different order, the fern -like plants, the Ophioglossacece. In these 
plants the young fronds do not unroll as they grow, the upper and fertile 
part is very different from the lower and sterile part. In one kind the 
lower part looks like an oval * and entire leaf (the whole plant resembles 
an orchid); in the other kind the lower part resembles a fern, but the 
upper is full of fruit and rolled together. 
After analyzing a few ferns, the learner will turn at once to the 
key,” which follows, and take up tribe I. If his fern is not a polypody 
(described in tribe I) he will turn to tribe II, and so on from tribe to tribe 
till he reaches the right one; when this is reached, he will turn to the 
genera (kinds of fern, such as NotholcEna, Pte7ds, Lomaria, etc.) passing 
from one to the other till the right genus is found. Then he should turn 
to the page where the genus is described. Let us suppose that it is the 
genus Cheilanthes (lip-fern) and the species Lindhemieri . After reading 
the description of the genus, and, being sure of it, the description in 
Italics following “ * ” should be read (and that onlyj; as it does not fit 
our plant, we skip everything to this likewise does not agree 
with the plant in hand, so we turn to ^^***”- this agrees, then we 
turn to ” under it; the description here does not fit, so we turn to 
-K- -f— ”; as this is the right one, we read under “ -m-”; this not being 
right, we read ”; as this is the right description we are now sure 
that the plant is C. myriophylla or C. Lindheimeri. We read the descrip- 
tion of each and decide that it is Lindheimer’s lip-fern. It takes but a 
few minutes to find the correct name of a fern in this way, and it is a 
pleasant task ; but if there were no key we should be compelled to read 
every description before deciding what our plant’s correct name is. 
§ 7- What Next? Having found the correct name of our fern, shall 
* See Glossary for definition. 
