2 Campbell. — Observations on the Development 
that the embryogeny has not been worked out before, as the 
spores germinate without difficulty. 
The Marattiaceae at the present time include four genera, 
with about 25 species, confined exclusively to tropical regions. 
In a fossil condition they are much more numerous and 
diversified than at present, and according to Solms-Laubach 1 2 
comprised the great majority of the Carboniferous and pre- 
Carboniferous ferns. Their great antiquity, as well as their 
morphological peculiarities, point to their being primitive 
forms, and this makes any information concerning their life- 
history of especial interest. As I have endeavoured to show 
in several other papers, there is constantly accumulating 
evidence pointing toward the Eusporangiatae as the forms 
from which the leptosporangiate ferns have descended, and 
we shall see that this view is still further strengthened by 
a study of Marattia. 
Up to the present time, we have almost no information 
concerning the embryogeny of the homosporous Eusporan- 
giatae, except Farmer’s 1 recent paper on Angiopteris , and 
this being the case, it is hoped that the present paper may 
have some interest, as adding somewhat to our knowledge of 
this important group. 
Marattia Douglasii is the only representative of the order 
found in the Hawaiian Islands. It is a large fern with 
massive leaves, two to three metres in length. It is common 
in the damp forests at an elevation of 300-400 metres, and 
occurs upon all the larger islands. The prothallia were found 
growing thickly upon clay soil near the plants, and were 
easily distinguished from ordinary fern-prothallia by their 
fleshy consistence and darker green color. Most of them 
already had young plants of various sizes attached to them, 
but a number were found with young embryos. The material 
was fixed with one per cent, chromic acid, and then gradually 
transferred to alcohol for study after my return to California. 
1 Solms-Laubacb, Fossil Botany, pp. 142-152. 
2 Loc. cit. 
