Hymenophyllaceae , Schizaeaceae and Gleickeniaceae. 513 
is bounded by the endodermis) resembles the dichotomy of 
the stele of Lyg odium (Boodle, ’ 01 , p. 365), and the behaviour 
of the phloem in the region of branching gives no evidence 
for reduction from solenostely. Attention is drawn to this, 
because in Osmunda cinnamomea the special behaviour of 
the phloem in the region of forking (viz. the presence, of 
internal phloem there and its continuity at times with the 
outer phloem) has been used by Faull (’ 01 , p. 41 1 et seq.) 
and by Jeffrey (’02, p. 126) as one of their grounds for 
regarding the present structure of O. regalis , & c., as derived 
from a solenostelic (amphiphloic siphonostelic) type. 
Without giving any very decided opinion as to the origin 
of the stelar structure of Osmunda , the writer wishes to 
emphasize : firstly, the importance, in any case where phylo- 
genetic consideration of structure is concerned, of examining 
a large number of specimens of a given species — as was done 
by Faull in O. cinnamomea , &c. — so as to obtain any indi- 
vidual structural variation that occurs within the species ; 
and secondly, the necessity of a very careful scrutiny of the 
results in the light of all available evidence suggestive of 
reduction on the one hand or advance on the other. Compli- 
cation of structure restricted to a region of branching, just 
like complication at a node, should be accepted with great 
caution as a primitive structure, unless it be supported as 
such by weighty independent evidence. 
While acknowledging the excellence of the observations 
detailed in Faull’s paper, it may be pointed out as a serious 
omission that the seedling-stem of Osmunda cinnamomea is 
not described in greater detail. One gathers from the state- 
ments on pp. 396 and 410 of Fault’s paper, and on p. 125 
of Jeffrey’s paper (Jeffrey, ’ 02 ), that internal phloem is not 
present in the transitional region of the stem, but only occurs 
near the region of branching of the stem 1 . This being so, 
a grave difficulty arises, for we have two alternative views. 
1 In Osmunda regalis Leclerc du Sablon (’90) found in the transitional region 
a pith with no internal phloem, and Seward (’03, p. 241) found the same in 
Todea hymenophylloides. 
