104 
Improvement of the Plants of the Farm. 
cow-grass by itself. It is quite as good a preparation for wheat as the common 
red clover, and grows with a similar tap root. I generally sow 2 lb. more seed 
per acre than in the case of red clover, as the seed is rather larger than that 
of broad clover as a rule. It has been grown in this neighbourhood over 
twenty years. 
" Unlike broad clover, after you have cut it for hay you cannot seed it, but 
it grows sufficient to fold the sheep with. I am doubtful whether it would 
stand a second year after being saved for seed. Two or three farmers in the 
neighbourhood generally save some for seed." 
To these practical reports I am able to add the following by 
Dr. Masters, F.R.S., to whom I had forwarded specimens of 
red clover, " single-cut cow-grass," and T. medium : — * 
" Sutton's ' single-cut cow-grass ' is to my mind only a variety of our 
common red, or broad-leaved clover, and is, 1 presume, a ' selection ' from it ; 
but its marked tufted habit and late development are, I should think, good 
qualities under certain cases. 
"I should have thought that 'single cut' might have been rejJaced by 
' cut-and-come-again,' provided the first cut were made early enough ; but I 
suppose experience shows the latter-math to be of little value. 
" As to the perennial character, I fancy that might be enhanced by early 
cutting, before the flower-heads are well advanced. The cutting or browsing 
(if done early enough) would have a tendency to cause the stock to branch 
out and form new crowns ; of the practical advantage of this you would judge. 
I only speak from a physiologist's point of view. 
" The stems are apt to be hollow below and filled with pith above, because 
the rate of growth is faster outside than in ; the consequence is, that in the 
older portions of the stem the outside draws away from the centre, leaving the 
latter void. The amount of ' hollowness ' varies a good deal, even in stems 
from the same crown, according to stage of growth. Nevertheless, I fancy 
'Sutton's single cut' is the less hollow of the two ; and if it is of slower, later 
growth, that is just what might be expected. 
" T. medium is widely difl'erent. The root is very distinct, and the whole 
habit of growth such as to make it less serviceable, other things being equal, 
than the common clover. 
" The specimens afford a practical illustration of the meaning to be attached 
to the word ' species.' No one can say definitely what a species is, or indeed 
whether it is not a convenient figment of the imagination ; but we are able to 
form a good working notion by observation and comparison. For instance, I 
should say your English red clover and the single cut are one and the same 
species, in spite of their differences, because I should readily believe that they 
might have sprung fiom tlie same original stock within a relatively short 
time. T. medium is so different, that I should not believe (till it was proved) 
that it sprung from the same stock as the others, at least within the historic 
period ! At the same time the difference is not too great to forbid my enter- 
taining a reasonable conviction that, given geologic time, the 'medium' 
might have sprung from the same stock as the two others. If it be of hybrid 
origin, however, then tlie process would be much quicker." 
* I think it necessary to mention here, in support of some preceding: quota- 
tions fnjni practiciil farmers, tlint tlie opinion of tfiis eminent botanist, although 
entitled to tlie greatest respect from a bofanical point of view, does not accord 
with the received estimate of Iho agricuUiiial difference between "cow-grass" 
and " red clover." Tf\at difference; may bo thus stated : " cow-grnss " has n solid 
stem, "red clover " has a hollow stem. — Kvvr. 
