118 
VII LASTHEA. 
The mid-vein of the pinnules is sinuous, producing alter- 
nate venules, which have several branches, the anterior of 
which only bears a sorus, and this is generally situated 
about halfway between the midrib and the margin, so as 
to form a more or less distinct line, though in luxuriant 
specimens the sori become crowded and confluent The 
fructification is usually either confined 
to or most abundant on the upper part 
of the frond ; sometimes, however, 
extending down to the second pair 
of pinnae from the base. The sori are 
covered by reniform indnsia, which 
are somewhat irregular on the margin, 
but without glands, and are attached 
by a deep sinus, the anterior margin 
being free. The larger of the two an- 
nexed figures of this fern represents 
a barren cultivated frond, and the 
smaller a wild fertile frond drawn to 
a more reduced scale. 
The variety uliginosa is exactly 
intermediate between what we take as 
the normal forms of L. cristata and 
Li. spinulosa, differing from each in 
certain particulars in which it agrees 
with the other. It has a stout de- 
cumbent caudex, and erect linear- 
lanceolate fronds, two to three feet 
high, and bipinnate at the base of 
the pinnae. It bears three kinds of 
fronds. When the young fronds of a 
mature plant are produced, which 
[Lastrea nliginosa!] usuaHv takes place ^^ days ^5^ 
than in the case of L. crista (a and later than that of L. 
gpinulosa, some of them are fertile and others barren. 
The latter are somewhat spreading, smaller, pinnate, 
with decurrent oblong-obtnse pinnules, and exactly re- 
