ANATOMY OF EQUISETUM GIGANTEUM . 
IsaBEL M.. P. BROWNE. 
(WITH SEVEN FIGURES) 
I.’ - Material 
While studying the anatomy of the cone of Equisetum gigan- 
teum serial preparations were made of some of the upper nodes 
of the fertile branches. These branches are small and usually 
possess eleven ribs and bundles. They were collected in Chili 
by Professor R. C. McLEan, who most kindly handed them 
over to me. Serial transverse sections have also been prepared 
from the upper part of a large young main stem of EF. giganteum 
from the West Indies, for which I am indebted to Professor F. W. 
OLIVER. This series of sections extended from a level distinctly 
below one node to a point near the upper limit of the next node. 
The complete internode was about 1 cm. in length, and would 
doubtless have elongated much more. This stem had thirty-two 
bundles and ribs. 
So far as I am aware, all accounts of the ahatenay of E. giganteum 
since Mitpe’s (11) in 1867, are based upon a short description 
by GwynnE-VAuGHAN (7) that appeared i in 1901. As my observa- 
tions differ in some points from his, and in others supplement and. 
confirm the details given by him, it seems advisable to publish a 
short account of the specimens studied. 
II. Node of young main stem — - 
Taking first the large young vegetative stem, the sectinds 
possesses a wide central cavity, about 6 mm. in diameter, the total 
diameter of the stem being about 7.75 mm. The bundles are oval 
in shape, with the longer axis directed radially, and each is sur- 
rounded by a separaté endodermis.t The’ vallecular canals are 
about the size of the bundles arid of much the same shape as these. 
Under each rib of the stem is a tooth of sclerenchymatous fibers, 
In none of the internodes examined was any trace observed of me common 
outer sheath of the bundles figured by Muxpe (f/. 21, fig. 4). , 
447] [Botanical Gazette, vol. 73 
