CHARACTERS OF TRIBES AND GENERA, 155. 
With such a wide range many species have been described 
by authors on very slight characters, chiefly in difference 
` in size, for instance, in Moore’s Index 55 names are recor- 
} ded, of which only twenty-one are adopted as true species, 
3 and these in the “Synopsis Filicum" are reduced to sixteen. 
In many Aspleniew, plants while young and small produce 
fructification, and have been considered as distinct species, 
such is the case with Antrophyum nanum, Fée (A. obtusum, 
Bl.), which is described as not more than an inch in length, 
but on collating numerous sets of specimens it is impossible 
to come to any other conclusion than that the intermediate 
sizes, even from the smallest to 2 feet in length, are only 
the graduations of a single species, the difference being 
consequent on age and climatic influences. The principle 
of creating species of Antrophyum upon difference of size, 
might with equal justice be applied to the common Harts’- 
tongue Fern (Scolopendrium officinarum), fronds of which 
may be found in fructification from a little more than an 
inch to two feet in length. 
The species vary in the sporangia being immersed or 
superficial, of which the following are examples. 
* Sporangia immersed. 
A. lineatum, Kaulf. (v v.) (Polytenium, Desv.) ; A. im- 
mersum, Bory.; A. plantagineum, Kauilf.; A. Cumingii, 
Fée (A. latifolium, Reinw. non Bl.) ; A. reticulatum, Kaulf. ; 
A. semicostatum, Bl. 
** Sporangia superficial or slightly immersed. 
A. ensiforme, Hook. (Ic. Pl., t. 394, Second Cent. t. 70); 
A. lanceolatum, Kaulf. (v v.) ; A. Cayennense, Kaulf. (v v.) ; 
. A. latifolium, Bl.; A.Boryanum, Kaulf.; A. giganteum, - 
— Bory. SCH 
