66 Narrow-Leaved Spleenwort 
have been sown and have produced plants with some normal 
leaves and with other leaves showing, at a very early stage, 
similar abnormal lobes. 
In this fern, as in other Asflenii, the sori are borne on veins 
that stand in certain relations to the midveins, each sorus opening 
toward a midvein. Some veins occur that stand in one of the 
required relations to each of two midveins, and, as a result, two 
sori (diplazioid sori) sometimes occur on these veins, one sorus 
opening toward each midvein.* 
Each sorus is borne on a midvein’s primary branch, or on 
this branch’s superior basal branch, or on a veinlet of the latter 
next the midvein. The only veins that stand in one of these 
relations to each of two midveins, and, consequently, the only 
veins on which diplazioid sori occur, are the upper basal primary 
branches of the pinne’s midveins. These branches stand both 
in the relation of primary branches to the pinne’s midveins and 
(since the pinne’s midveins are primary branches of the leaf’s 
primary midvein), in the relation of superior basal primary 
branches of primary branches to the leaf’s primary midvein. 
Diplazioid sori occur only on the upper part of the leaf, perhaps 
for the reason that the leaf’s primary midvein, while showing its 
character as a midvein in that part of the leaf, apparently loses 
it below by becoming merged or concealed in the rachis. 
Whether the sori which go to form the diplazioid sori are 
diplazioid for the whole or only for part of their length depends 
upon how far they extend. One may extend farther along the 
upper basal primary branch of the pinna’s midvein than the 
other. At the upper end of this vein, if it divide into two veinlets, 
* For instances of the occurrence of diplazioid sori in other Asflenii, see pp. 72, 
89, and go. 
