Igt0] JEFFREY—PTEROPSIDA 405 
are able to make their way into it. If it is once conceded that 
such clearly extrastelar substances as ramentum-covered epidermis 
and the free external atmosphere are able to make their way into 
the interior of the stele, there appears to be little ground for ques- 
tioning that the cortex and its internal boundary, the endodermis, 
may penetrate the same sanctum sanctorum. In the present 
defunct condition of the growing-point hypothesis, it seems clear, 
in view of existence of such facts as those illustrated in the two 
figures just described, that the dogma of the stelar origin of the 
pith rests on an extremely weak foundation. 
It is admitted further, even by those who are most extreme in 
their support of the view that the pith is always of stelar origin, 
that, although the central cylinder of the stem cannot include 
within itself the outlying tissues of the cortex, this possibility 
exists in the case of the leaf trace. Mr. Boopte, the most logical 
and consistent of the younger English anatomists, and one whose 
contributions, together with those of Dr. D. T. GWYNNE-VAUGHAN, 
comprise the most important data on the anatomy of ferns which 
have recently appeared in England, not long since published an 
article on certain species of Gleichenia5 He here states that “the 
nearly circular or subcordiform petiolar bundle of Eugleichenia 
may be held to be derived from the horseshoe-shaped bundle of 
the Mertensia type by contraction, and by the fusion of the free 
ends of the horseshoe, the sclerenchymatous cortex in the concavity 
of the latter thus becoming inclosed, or at a higher level suppressed oe 
The present writer has italicized the significant part of the quota- 
tion. It is apparent that Mr. Boopre admits that the foliar 
trace may include cortical tissue. If such an admission is made in 
the case of the Gleicheniaceae, it cannot fail of application to the 
petiolar structures of other families of ferns. Let us take as an 
example, among many others, the case of the Marattiaceae. In 
fig. 3 is represented the vascular system of the base of one of the 
large pinnules of Angiopteris evecta. The bundles are arranged 
ina horseshoe-shaped manner, with the two large bundles terminat- 
ing the arms of the horseshoe turned inward and downward. 
‘ Boopte, L. A., and Hizey, W. E., On the vascular structure of some species 
of Gleichenia. Annals of Botany 23:419-432. pl. 29. 1909. 
