﻿18 MR. JOHN SCOTT ON THE TREE FERNS OF BRITISH SIKKIM. 



and steins of sixty fairly-developed frond-beariD g shoots, varying from 2 inches to 6 feet 

 in length, and from 3 to 13 inches in circumference. A. gigantea never (tlmt I have 

 seen) attains these proportions; and there is another note-worthy difference in the deve- 

 lopment of their respective buds. In A. gigantea simply pinnatifid fronds are produced 

 almost contemporaneously with the appearance of the bud as a distinct organ on the 

 stem, or before it is larger than a mustard-seed. On the other hand, in A. comosa, 

 from the appearance of the fronds, there is generally a considerable development of the 

 axial parts {vide Plate II.), which assume apyriform shape, enveloped upwards in brown 

 subulate scales, and below in a fascicle of short, slender adventitious roots. Thus ere a 

 single frond has appeared they have a sufficient amount of independent vitality to be 

 separated from the parent stem, and give rise to new individuals, presenting in this 

 respect an analogy to many other proliferous hill-j^lajits. 



The normal forking of the main axis I have observed in three of the Sikkim species, 

 viz. Alsophila latebrosa, A. ornata, and A. gigantea. In the two latter, however, rami- 

 fications occur much less frequently by this process than by the production of adven- 

 titious buds, which I have never observed on the first-named species : indeed ramification 

 in any form is rare in the extreme in this species ; and of the many specimens which I 

 have seen of it in the Sikkim forests, one only was branched, and that, singularly enough, 

 in a very striking manner, as is partially shown by the representation (Plate I.). This 

 specimen had a clear erect bole 25 feet in height, whence, nearly in a verticil and pro- 

 bably by division of the terminal bud, proceeded seven stout symmetrical branches. I 

 have said by division of the terminal bud, which I consider the more probable origin of 

 these shoots, as aU were in unbroken continuity with the main stem, and in this respect 

 differed from those originating as adventitious buds, which, moreover, I beHeve, as 

 just stated, are never produced by this species. At about six inches above tlie pseudo- 

 verticil one of the shoots bifurcates, as shown on the plate ; and again, at a hei-ht of 

 about 2 feet, two others are forked, thus producing a ten-Jieaded specimen. The indi- 

 vidual shoots are aU very perfectly developed, varying in length from 5 to 12 feet in cir- 

 cumference from 7 to 13 inches, and each surmounted by a corona of intertanglinr. fronds*. 



In the sketch of a triple-headed specimen (Plate IX. fig. 8) of A. ornata which I found 

 m Sikkmi, the origin of the ramifications is very clearly shown. The constriction 

 evident on the mam stem, immediately under the divisions, indicates the partial arrest 



t Wh tT. 'T : "r '" *^' '^''^'^ ^"^^^^^- ^' *^- -i--g force, 



though m the majority of instances division occurs without any apparent cause The 



structure of the stem in the above case had all the appearance, J^^^iT^noZ 



b 



When 



ikntations, and not in the midst of an nnfrequented 



■ 



as one that would indeed have been a prize to any 



'nnii 



addition to the museum. 





an aajoimng bustie, who had seen ns measuring 



portion of the stem, inelnding' the io^^^Z^TTZX Tv ' ''""' "^^ ?'="'• ^ '-'« »' »» *» ^aTO a 

 was hacied and mi^eed. ° ° ' """^ ' ''"* ""^ ^^"*^"» «"«™ ''^'1 ^Pared not even this remnant : all 



