— 54 — 
I his at best can only be considered an approximation; first, 
for the reason stated above ; second, because it is almost 
impossible to remove plants of the size of the ones with 
which we had to deal without loosing some leaves and 
stems, and still more difficult to get their original weight; 
for, do the best we could, evaporation from both roots and 
tops took place, though they did not show wilting to 
any extent. We weighed thirty-two plants, and the diffi¬ 
culty of the task may be appreciated in some measure when 
it is considered that the shortest plant handled, counting 
root and top, measured nine feet nine inches. The weight 
obtained for the roots is very nearly correct ; while the 
weight of the tops is far too low, for the plants were al¬ 
ready in seed when they were dug, and the loss by breakage 
and falling off of leaves was large, and to this is to be add¬ 
ed the loss due to evaporation, which was unavoidable, as 
many of the plants which we weighed were secured twelve 
miles from the laboratory. There was no way of deter¬ 
mining this loss, and we have no basis on which to esti¬ 
mate it. I he closest approximation that we can make is 
on the following basis : first, assuming that the roots which 
we_ weighed were representative, we find their average 
weight to be 106.5 grams, green weight ; second, we are 
justified by actual count in assuming that a good stand of 
five-year old alfalfa has about 140,000 plants to the acre : 
third, experiment indicates that the stubble is equal to 
about one-sixth of the green crop ; fourth, five-year-old al¬ 
falfa referred to cut two and one-quarter tons of hay to 
the first cutting last year (1895), or 5.000 pounds, adding a 
loss of about twenty per cent. Seventy per cent, of the 
green crop is water, and thirty per cent. hay. All 
these data are based upon determinations made with as 
much accuracy as the subject will permit. Before proceed¬ 
ing with this calculation, it should be observed that the 
weight of the roots of the smaller plants exceeds the 
weight of the tops, sometimes being over three and one- 
fourth times as heavy. If the smaller ones are nearer the 
average, as is probably the case, the weight of the roots 
will exceed that of the tops of any single cutting. 
Basing our calculations on these results, we have 
the two and one-half tons of hay, corresponding to 16,666 
pounds of green crop ; now adding one-srxth for stubble, 
gives us 19,443 pounds, or 9.72 tons. With 140,000 roots, each 
weighing 106.5 grams, we have, taking one pound as equal 
453-4 grams, which is near enough for our purpose, a 
total of 16.44 tons of roots, ora ratio of 1.69:1 for the 
roots to the total tops produced at this cutting, which 
