the Ophioglossaceae. 11 
leaf-trace there break off other sets of strands ; those which break off from 
one edge supply the second spike, and those from the other edge supply 
the third spike. In other words, the vascular supply of the first spike is 
derived from both edges of the leaf-trace, while that of subsequent spikes 
may be derived from only one edge. According to the reasoning here 
employed, it may be inferred that the lowest spike in this specimen 
represents two fused lobes of the leaf, while the next two spikes represent 
single lobes. Whether any particular spike arises from one or from both 
edges of the leaf-trace can be determined only by the study of serial 
sections, and not by an inspection of the external surface, as has too often 
been done. Bower lays much stress on the observation that the spikes 
do not generally arise from the margin of the leaf, yet the only transverse 
sections which he figures (6, p. 463) clearly show that in the case of the 
three spikes so represented the origin of the vascular supply at any rate 
is truly marginal, i. e. derived from the free edges of a curved leaf-trace 
made up of a number of separate strands. Probably most morphologists 
would place more reliance on the disposition of the vascular skeleton than 
on the superficial ‘ flesh ’ which clothes the skeleton. 
The monotypic Asiatic genus Helminthostachys presents points of 
considerable difference from the other two genera. Farmer and Free¬ 
man (11) have given the best account of the mature sporophyte, while 
the young sporophyte is considered by Lang ( 16 ) in his paper on the 
gametophyte. By means of material kindly supplied by Dr. J. C. Willis, 
Director of the Royal Botanic Garden at Peradeniya, Ceylon, I have had 
the opportunity of verifying earlier accounts, while I have been able to 
study the structure of a young specimen kindly placed at my disposal by 
Professor Jeffrey of Harvard University. In the mature plant the single 
leaf-trace forks before it emerges from the cortex of the creeping rhizome, 
and soon repeats the process several times, forming a nearly circular row 
of eight to ten strands which soon become concentric. From one of the 
adaxial edges of this broken circle a strand breaks off, 1 turns towards 
the middle region of the petiole, and orients itself in the inverse position. 
Thus a section through the petiole shows a ring of bundles with an odd one 
in the middle, frequently somewhat nearer the adaxial side. Campbell ( 9 ) 
figures a specimen with two strands in the position of the odd bundle, 
and says that these strands ‘ remain separate and are those which later 
extend into the spike \ Inasmuch as this condition is not represented in 
any of the figures of Goebel ( 13 ), Bertrand ( 2 ), or Tansley ( 24 ), nor shown 
in my material, it would be very interesting to know whether it is the 
result of splitting of the odd bundle, or whether each of the bundles arises 
from one edge of the curved leaf-trace. Campbell’s account gives no 
1 This fact, I believe, was first pointed out by Gwynne-Vaughan in his paper on Archangioptens 
(Ann. Bot., xix, 1905, p. 259). 
