534 Farmer . — On the Structure of a Hybrid Fern. 
me his extensive collection of plants at the Chelsea Nurseries, 
and I have no doubt whatever as to the genuine hybrid 
nature of the Fern, both on the ground of what I saw there, 
as well as on account of the strong evidence in its favour 
furnished by the comparative study of its anatomy. The 
results of the successive fresh raising of the hybrid were 
strikingly uniform, the intermediate characters being prominent 
in all. 
In the robust habit of growth and in its thick and densely 
ramentose rhizome, the hybrid approximates far more closely 
to the character of P. aitreum than to that of P. elegan tissimum 1 2 , 
which possesses, relatively speaking, a slender rhizome which 
is not specially densely clothed with scales. Again, the 
presence of these ramenta (although but sparsely scattered) 
on the rachis of the young fronds of P. aureum , and, though 
in a less degree, on those of P. Schneideri also, appears in 
marked contrast with the naked leaf-stalk of the other parent. 
And this is the more singular inasmuch as in other respects 
the general appearance of the frond of the hybrid, save in 
its far larger size, very closely resembles that of P. elegan - 
tissimum , and is not at all like that of P. aureum. 
It has been said that P. elegan tissimum shows a tendency 
to ‘ revert 2 5 to the simpler form of P. vidgare , and the same 
peculiarity is manifested in its bastard offspring. Sometimes 
only a few pinnae, or even a half-pinna, may exhibit the 
‘reversion 1 (PI. XXIV, Figs. 17, 18); sometimes it extends 
to all the leaves on a branch (Fig. 19), and I saw a number 
of plants obtained from cuttings of such branches which 
had grown and remained true. But the greater number 
of reverted fronds of the hybrid were not quite like those of 
the P. vidgare type. Some of them exhibited the bluish 
bloom, and others the peculiarly wavy texture so character- 
istic of P. aureum. It was in the general outline that the 
1 I use the curtailed form of the name for the sake of brevity. 
2 The use of the terms ‘ revert ’ and ‘ reversion ’ is merely one of convenience, 
and is not intended as implying an expression of opinion on the general questions 
of atavistic or discontinuous variations. 
