ON REPRODUCTION. 375 
their appearance at Kew, the only specimen in this country 
then known being in the herbarium of the British Museum, 
which I had not then seen. The botanical collector, Allan 
Cunningham, failed to find it in Tasmania, and was very 
much surprised on my presenting him with fine specimens 
grown at Kew. This was also the case with Doodia 
blechnoides, and Asplenium squamulata, by what means the 
spores of these plants found their way into the pots at the 
hothouses at Kew it is impossible to say. 
In spite of the very delicate nature of the prothallia, 
it is nevertheless endowed with great vitality, as may 
be seen by Ferns appearing on dry rocks, walls, and 
such like, resisting the extremes of heat and cold. For 
example, in 1829, I found a plant of Ceterach officinarum 
growing in a crevice of masonry on one of the towers of 
the new palace at Kew (since taken down). As this Fern ` 
is not found wild near London, it would be useless to 
speculate where the solitary spore came from; it seemed, 
however, to have found a proper nidus in the crevice, 
enabling it to germinate and resist all untoward influences, 
to pass through the prothallium state, and become a plant. 
I must here state, that not long after Count Suminski’s 
discovery became known to me my sight began to fail, 
which necessitated me to give up the use of the microscope, 
therefore my own practical observations on this important 
subject are but limited. 
In many cases Ferns not only reproduce their like by 
spores, but also by the viviporous buds generally produced 
on the upper side of the frond, or on the apex of the fronds 
or segments, which when mature become plants. This is 
specially characteristic of many species of Asplenium, 
—. Goniopteris, Woodwardia, Meniscium, and others; but so 
. far as has come under my notice, no bulbils are produced 
