Stem of A ngiopteris evecta. 
52 i 
Conclusion. 
Since the anatomical structure of the stem of Angiopteris 
evecta has been described in most detail by Mettenius, it is of 
interest to compare with his results those now obtained. 
The arrangement of the vascular strands in a series of 
inverted funnel-shaped zones is the same in both stems, but 
the closing up of the strands into continuous rings in the 
upper part of the stem, in the way described by Mettenius, 
must certainly be attributed to the unhealthy life of the plant 
for some time before its abandonment to the purposes of 
scientific research. There was not the slightest trace of such 
an altered structure in the apical regions of the plant from 
Ceylon. 
Further, my investigations show that the leaf-trace bundles 
arise from superficial vascular tissue alone, and that the steles 
of the second zone do not share in the formation of the foliar 
strands, which are indefinite in number and position. This 
was not the case in the stem described by Mettenius, for here 
two bundles from the second zone passed off into each leaf, 
and the foliar strands were constant in number and arrange¬ 
ment. The difference in character of the foliar bundles in the 
upper and under leaves in Mettenius’ plant is, of course, to 
be correlated with the difference in the vascular system in the 
stem in the two cases. 
The stem just described presented definite dorsiventrality, 
both in its external characters and internal structure. The 
roots were produced in great numbers on a certain part of 
the lower surface of the stem, and diminished in number 
towards the apex. This latter fact is also noted by Mettenius, 
who attributes it to the altered conditions in the nutrition of 
the plant \ 
The wearing away of the base of the stem described in 
the preceding pages did not allow of any conclusion as to 
the original structure of the vascular system in this part; 
1 Mettenius (’64), p. 517 . 
