CRYPTOGAMS 345 
be taken in collecting specimens, as in their early stages the prothallia 
bear a strong resemblance to certain liverworts found in the same situa- 
tions. The best way is for each class to raise its own specimens by scat- 
tering the spores of a fern in a glass jar, on the bottom of which is a bed 
of moist sand or blotting paper. Cover the jar loosely with a sheet of 
glass and keep it moist and warm, and not in too bright a light. Spores 
of the sensitive ferns (Onoclea) will germinate in from two to ten days, 
according to the temperature. Those of the royal fern (Osmunda) ger- 
minate promptly if sown as soon as ripe, but if kept even for a few weeks 
are apt to lose their vitality. The spores of sensitive fern can be kept 
for six months or longer, while those of the bracken (Pteris) and various 
other species require a rest before germinating, so that in these cases it 
is better to use spores of the previous season. 
402. Study of a typical fern.— Observe the size and 
general outline of the fronds, and note whether those of 
the same plant are all alike, or if they differ in any way, 
and how. Observe the 
shape and texture of the 
divisions or pinnse com- 
posing the frond, their 
mode of attachment to 
the rachis, and whether 
they are simple, or 
notched, or branched in 
any way. Hold a pinna 
up to the light and notice 
the veining. Is it like any 
of the kinds described in 
171,:172? In what re- 
spect is it different? 
This forked venation is 
a very general character- 
istic of ferns. When the 
forks do not reticulate or 
intercross, the veins are Fis. 487-491.—A fern plant: 487, fronds 
i 7 h and rootstock; 488, fertile pinna: s, s, sori; 
said to be free ; are t €Y 489, cross section of a stipe, showing ends of the 
J specimen, or fibrovascularbundles ; 490, aclusterof sporangia, 
free Tm Your SP 4 magnified ; 491, a single sporangium still more 
reticulated? Make a magnified, shedding its spores. 
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