— 53 — 
nodules were nearly spherical and were from an inch to an 
inch and a half in diameter. Some were irregularly hemis¬ 
pherical and nearly two inches long. Others resembled the 
antlers of a stag, some of the individual portions having a 
length of more than half an inch. Compared with the 
nodules on the vetch and red clovers, as they grow in our 
soils, the alfalfa is but poorly supplied with them ; this is 
particularly true with some of the vetches, but the groups 
of these nodules are incomparably larger on the alfalfa. 
The branched groups occur on the vetches as well as on 
the alfalfa. 
Some of these groups were submitted to a partial analy¬ 
sis. The samples were obtained from plants growing in a 
rich, dark loamy soil. The groups were found about three 
and one-half feet from the surface and rather more than 
this from the permanent water below. They were washed 
to remove the sand and dried between filter paper. The 
nodules contained 61.67 per cent, of moisture and the dried 
material 5.725 per cent, of nitrogen ; while the bark of the 
roots contained 2.25 per cent, nitrogen. This included any 
nodules which chanced to be on the bark. No attempt was 
made to avoid them. The washing of both the roots and 
the nodules was quite unavoidable. There is no doubt that 
the composition of each was altered by the process ; not 
enough, however,to materially detract from the significance 
of the results. The effect of washing the roots is described 
elsewhere. 
RATIO OF THE ROOTS TO THE TOP. 
The largest root which I dug up, was twelve feet six 
and one-half inches long, and the average diameter of all 
the roots measured (150) is one-half inch at the crown, and 
one-third of an inch, six and a half to seven inches below 
the crown, or at the average depth of plowing. The tops 
on the other hand at a period of their growth vary even 
more than the roots do, varying exceedingly as to the 
number of. individual stems, and these vary even more in 
their thickness, leafiness and hight. In a plant of one sea¬ 
son’s growth, having but few stems and these slender, the 
root may be several times heavier than the top; and on 
the other hand the top of a favorably located plant may at¬ 
tain a weight of from four to seven and even more pounds, 
green weight, while the root will seldom exceed a pound. 
Our heaviest root weighed 418 grams, equal to about 
thirteen ounces, and was nine feet nine inches long 
Taking the average of all the plants which we have 
weighed, we find the ratio of roots to tops to be 1 : 1.3. 
