494 Stosson : THE ORIGIN OF 
and elsewhere it resembles in some of the leaves that of mature C. 
rhizophyllus and in others that of mature A. platyneuron. But, 
supposing A. ebenoides and the hybrid to have arisen in the same 
way, for some of the progeny of the same parents to resemble one 
parent and for others at the same stage of development to resemble 
the other, is so common an occurrence that no comment Is re- 
quired. From the figures, in which C-and CC represent leaves of 
A. ebenoides from Havana Glen, this varying resemblance of A. 
ebenoides and of the hybrid, at various stages of development, to C. 
rhizophyllus or A. platyneuron may be seen. It is especially notice- 
able in figures 1-3. 
Of characteristics possessed by A. edenoides and not by the 
hybrid I find but two: 
1. Possession of sori. The lack of this characteristic in the 
hybrid is easily accounted for by the age of the plants. The plant 
are still growing and it is confidently expected that sori will de- 
velop upon older leaves. 
2. Elongation and attenuation of the pinnae. But this char- 
acteristic is either not constant in A. ebenoides or else appears ™ 
different plants at different stages of development. It is very 
marked and seems to appear, as a rule, at an early age, in most 
specimens of A. ebencides from Havana Glen. On the other hand, 
Dr. Murrill tells me that it did not appear in his plants from bia 
ginia until they had been kept for some time in a greenhouse, in a 
favorable environment which caused them to develop luxuriantly. 
In one of his specimens that show no trace of it the blade of the 
leaf is fully 10.797 cm. long, about a third longer than that of the 
largest leaf of the hybrid plants, and well fruited. None of the 
leaves of the specimens of A. ebenoides found by Dr. C. E. Waters 
in Maryland show elongation and attenuation of the pinnae. s 
the utmost that can be said of the lack of this characteristic g 
leaves of the hybrid is that they resemble some leaves _ 
ebenoides rather than others. How close the resemblance ' 
be seen by comparing B and BB, f. 7, which represent ee ‘ 
the hybrid, with C and CC, f 7, which represent leaves © 
ebenoides, us 
Thus, on comparing. with A. ebenoides a fern pe to 
crossing A. platyneuron and C. rhizophyllus, it is found simile 
