— 4 6 — 
simple tap root, running down to from three to five feet 
and then sending off a few side roots, or rather 
dividing into a few branch roots about equal in 
size and length. These branches do not, as a rule, de¬ 
viate more than a few inches from the course pursued 
by the tap root before division. I have in no case found 
a system of small roots starting out below and near the 
crown, extending laterally for several feet and then turn¬ 
ing downward, forming a symmetrical conical system, 
whose broadest part was near the surface. The absence 
of such roots was a matter of note to me, but after hav¬ 
ing observed it in upwards of three hundred and fifty 
instances, I was satisfied that it was a habit of the plant. 
In cases where I found any root or roots setting out from 
the tap root immediately under or near the crown, they 
were large, usually as large as any of the roots formed by 
the branching of the tap root, and in every instance in 
which I was able to follow them to the end, they extended 
to almost or altogether as great a depth as the tap root it¬ 
self or any of its divisions. When such side roots occured, 
we found but few of |hem, as a rule only one or two. This 
is well shown in one of the plates. The tap root, as well as 
all its divisions, are remarkably smooth and free from fibrous 
roots. The tap root is often perfectly smooth, save for the 
wart-like excressences on it, caused by its symbiotic mi¬ 
cro-organisms ; so much so that it can be removed after 
having been properly exposed, leaving a perfect cast of the 
root in the undisturbed soil. Close investigation of the 
adjacent soil has failed to show small roots even a few 
inches in length, such as may be found practically possess¬ 
ing the ground for many inches—twenty or more—about the 
vetch, tomato, or almost any of our garden plants. It may 
be stated here that the plants studied had not been culti¬ 
vated, that is, the soil about them had not been disturbed 
from the time the seed was planted until the plants were 
dug up, except in cases where the fact will be explicitly 
mentioned. 
The absence of these small fibrous roots has been and 
still is perplexing, as it was anticipated that such a vigor¬ 
ously growing plant would be well supplied with such, each 
provided with its spongiole to provide the plant its neces¬ 
sary sustenance. While the number of spongioles found 
was in the aggregate large, it was much smaller than ex¬ 
pected and the spongioles were at the extremities of the 
roots themselves and almost exclusively at a depth corre¬ 
sponding to that attained by the root. This observation is 
in perfect accord with the usual statement that alfalfa is a 
