VOLUME LI NUMBER 2 
A Ges eS 
BOTANICAL. GAZETTE 
FEBRUARY 1sgit 
THE ANATOMY OF THE SPORELING OF MARATTIA 
ALATA 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 142 
Grace Miriam CHARLES 
(WITH PLATES IX-XII AND THREE FIGURES) 
The Marattiaceae combine to a unique degree the interest of an 
extremely ancient family with the significance of connections not 
only with other fern families but with the origin of seed plants. The 
recent discovery of the latter connection calls for more knowledge 
of the vascular anatomy of the living Marattiaceae, based upon 
abundant material. 
Historical 
The first studies of the anatomy of the Marattiaceae were 
based upon the mature stem of Angiopteris evecta. As the anatomy 
of this genus is the most complicated in the family, the first investi- 
gators, De Vries and HartING (7), in 1853, concluded that the 
vascular system is composed of a tangled net of bundles running in 
every direction through the stem; and that the strands make a 
spiral of several cycles, which finally run out into the leaf traces. 
They made no distinction between leaf traces, stem bundles, and 
cortical roots. 
_ In 1864 Merrentus (21) investigated the stem of a large plant 
of Angiopteris evecta that had been languishing for eleven years 
before it was used for research. He considered that the vascular 
tissue is arranged in a series of concentric meshed zones or funnels, 
whose apex is at the base of the main axis of the stem and whose 
obliquely running bundles pass off from the periphery as leaf traces; 
that these leaf traces contain a definite number of bundles from 
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