166 BULLETIN OF THE BUSSEY INSTITUTION. 
No. 16.— On the Chemical Composition of the Common Field 
Horse-Tail or Scouring-Rush (Equisetum arvense). By F. 
H. Storer, Professor of Agricultural Chemistry. 
Few plants have been more cordially detested by dairymen than 
the familiar horse-tail (Hquisetum arvense), which grows abundantly in 
many damp places; and there would seem to be little reason for doubt- 
ing that horned cattle are liable to serious injury from feeding upon 
it, though horses and sheep are said to be fond of the plant, and to feed 
upon it without injury as a general rule. 
There is need enough, no doubt, of studying in detail the question, 
Why is it that the plant injures horned cattle? But I am in no posi- 
tion to undertake the solution of a problem of this kind, and have been 
forced to content myself for the present with a mere chemical examina- 
tion of the plant in the interest of those. kinds of animals which can 
feed upon it with impunity. I have had the curiosity, moreover, to 
contrast the chemical composition of the so-called fertile stems of the 
plant, which bear its spores or fruit, with the sterile stems, which sim- 
ply bear branches.* F 
Considered as forage, the fertile stems are specially interesting, be- 
cause of their early appearance and their brief term of life. They 
shoot up quickly from the root-stocks in early spring, like the aspara- 
gus sprouts, whose appearance they so much resemble; and, after bear- 
ing the spores, they shrink away, decay, and disappear, with equal or 
even greater rapidity ; while the more familiar branching sterile stems 
come up in their turn from the root-stocks to replace the spore-bearing 
sprouts. If the fertile stems were really a useful kind of fodder, it 
would manifestly be important to let the pasturing animals have access 
to them at once as soon as they appeared, lest they should die uneaten, 
and so be lost altogether. 
The specimens examined were obtained as follows : — 
I. Fertile stems of Hguisetum arvense, collected by my friend, Mr. 
Charles Wright, April 21, 1876, upon a moist railway embankment 
near the Bussey Institution, between Forest Hills and Mount Hope. 
* Compare Gray’s “ Manual of the Botany of the Northern United States,” 
p. 585, Article Lguisetacee, 
