Macroglossttm Alidae , Copeland. 66 1 
vascular system was composed entirely of leaf-traces. Several of the young 
sporophytes of Macroglossum were cut transversely for comparison with the 
other Marattiaceae, and, as in these, it was clear that the vascular system of 
the stem is at first composed of the leaf-traces alone. Text-fig. 5 shows 
several sections taken from such series. These sections resemble more 
nearly corresponding ones of Danaea than of Angiopteris , the leaf-traces 
remaining separate for a longer time than in Angiopteris. In the 
sporophyte figured below the fourth leaf-trace was just visible. A is 
taken a short distance below the stem-apex, and shows the four leaf- 
traces completely separated. Close to the fourth leaf-trace is the begin- 
ning of the fourth root (r 4 ). The leaf-traces in all cases show a con- 
centric structure, and as the sections from the older part of the plant are 
examined, the leaf-traces are seen to converge, and finally unite into 
a central strand. In C the second and third traces are completely united, 
Text-fig. 5. Four sections from a series of a sporophyte in which the fourth leaf was still very 
young, x 25. The roman numbers show the leaf-traces; i A , the fourth root; r 1 , section of the 
second root. 
but the primary leaf-trace is still free. In D is shown a section in the 
transition region between the cotyledon and primary root. The triarch 
second root (r 2 ) is shown also in this section. 
Sections from the middle and basal regions of an older sporophyte 
confirm the impression that the central vascular strand or ‘stele’ is the 
result simply of the fusion of independent leaf-traces, and there is no 
evidence of its being continued as an independent strand into the stem- 
apex. It is likely, however, as happens in the other genera, that later 
truly cauline bundles make their appearance, but this point was not 
investigated. 
While Macroglossum resembles Danaea in the arrangement of the 
vascular bundles in the very young sporophyte, in other respects it is more 
like Angiopteris. In Danaea and K aulfussia, mucilage ducts are formed 
at an early period, while they seem to be quite absent from the young 
Y y 2 
