Observations on the Vascular System of Ferns. 113 
and connécted with the poles of a battery by the separate 
and cups (pm.) The centre of this box is open to adm 
shaft of the magnet, as is also the centre of the box (e.) 
box is made of two glass cylindrical sections, cemented int 
groove of a turned cup or base of wood. It contains two ‘dis 
for mercury nearly semicircular, and insulated from each other 
precisely as the cells for the Ritchie magnet. ‘These cells are 
connected with the extremities of the spiral by the separate wires 
and cups (a b.) ‘Fhe two wires (i7) are well insulated by a 
winding of varnished silk, and secured in their positions on the 
shaft by silk thread. 'The upper extremities of these wires dip 
_into the concentric cells of (d,)-and the lower into the cells 
of box (e.) The base board is made thin, and the pivot (g) 
short, to allow the magnet to come as near as possible to the 
spiral. Place the instrument upon the spiral, make the connex- 
ions as above directed, and the magnet immediately commences 
a rapid rotation by the influence of the spiral. ‘The instrument 
should always be placed without the centre of the spiral, and in 
such a manner, that the insulating pieces between the cells of 
(e) should be in the direction of a radius of the spiral. 
Art. VIII.— Observations on the Vascular System of Ferns, and 
Notice of a monstrous flower of Orchis spectabilis ; by J. W. 
Battery, Professor of Chemistry, Mineralogy and Geology, at 
the U. S. Military Academy, West Point. 
= . I. On the Vascular System of Ferns. 
) Tri isa Lcpalniens of much interest in vegetable anatomy, sister 
p vessels exist in ferns; for if they do, ferns present a remark- 
=, able deviation from the usual structure of flowerless plants. It 
4 ‘ is well known, that the presence or absence of these vessels has 
been considered so invariably connected with the presence or ab- 
sence of flowers, as to have given rise to the division of the vege- 
table kingdom into_the two great classes Vasculares or Flower- 
! ing, and Cellulares or F'lowerless Plants. Ferns are by all writers 
| placed in the last class, but it will be seen by the following quo- 
| tations, that there exists much uncertainty with regard to their 
having spiral vessels. 
Vou. XXXV.—No. 1. 15 
