BOTANICAL GAZETTE. 359 
exceptions, but even here it was rare. Aspidium spinulosum, to 
judge from naturally grown specimens, 1s moncecious, no un- 
doubted male prothallia being found, and perfect antheridia oc- 
curring on the large prothallia. Cystopteris fragilis was found 
with two forms; small male prothallia, and large hermaphrodite 
ones. In regard to other forms, observations were too incomplete 
The male prothallia of all the forms observed are, as a rule, 
very much smaller than the female, and frequently of very irreg- 
ular shapes (Figs. 8, 9,10). Either no definite apical cell is 
formed, or it is early lost. Where the spores are sown thickly it 
id cells terminated by an antheridium, other antheridia being 
ormed laterally in some cases, in others not. 
e simplest form observed was that of Asplenium filix-foemina, 
Where a number of prothallia were formed whose vegetative por- 
tion was reduced to a single cell besides the root-hair (Fig. 7). 
Bee antheridium was formed in each, and perfect anthero- 
th Under favorable circumstances the spores germinate in from 
"ie to five days, but in cold weather, or with imperfect spores, 
a was indefinitely lengthened. The firs | 
* y mature in about five weeks from the first signs : 
nation, but in one case, Asplenium, ripe antheridia were forme 
Nalittle more than three weeks from the sowing of the spores. 
: heridia on September 
The prothallia in this ease were reduced to a very few cells. 
Spores of Onoclea Struthiopteris, sown on February 25, 1884, be- 
theridia 
and laid aside. In October, 1884, a number of the spores were 
laced ; 
Placed in water, and in about 'a week began to grow. 
lia will live for compara 
