390 
Composition and Nutritive Value of Strmv. 
fibre affects the nutritive value of all food in no mean degree. 
Whilst in root-crops left too long growing on the land, or the 
fibre of grass and clover left standing until dead-ripe, these 
tissues are not readily digested, there can be no doubt that 
the soft fibre of young grass, clover, and roots is readily 
assimilated in the animal organism, and transformed into starch, 
sugar, and finally into fat. For this reason grain-crops, more 
especially oats, when harvested early, produce straw which 
is greatly more nutritious than that of an over-ripe crop. In 
some parts of Scotland it is customary to cut the oat when the top 
of the haulm is still quite green ; and it is upon straw of that 
description that store cattle are kept during the winter almost 
entirely. The variable condition in which grain-crops, as Avell 
as peas and beans, are harvested in England, fully explains the 
various shades of opinion which are entertained by practical men 
respecting the feeding properties of the straw of these crops, and 
the contradictory statements of writers on this subject. 
For the same reason the practical solution of the question 
whether woody fibre is digestible or not, is surrounded by pecu- 
liar difficulties. Taking experience for our guide, it may be 
answered with equal truth in the affirmative or in the negative ; 
lor in a young, tender condition we know from experience that 
cellular and woody fibre is digestible, whilst in a hard, dry, 
over-ripe state it is for the most part indigestible. Direct feeding 
experiments, highly desirable though they may be, will leave 
much uncertainty, however carefully they have been made, 
unless special regard is paid to the condition in which the straw 
is given to the animals ; and after all, as it is not possible to 
describe with absolute precision its state of maturity and condi- 
tion, no practical feeding experiment, be it ever so carefully 
conducted, can afford absolute numerical results, indicative of the 
extent to which the woody fibre is digestible in all, or even the 
majority, of instances. 
Feeding experiments instituted for the purpose of ascertaining 
to what extent the woody fibre of food is assimilated in the 
animal organism are highly desirable, but at the same time they 
are most laborious and costly. They require to be undertaken 
on a tolerably large scale, and cannot well be executed by a prac- 
tical farmer, for want of scientific appliances, nor even by an 
agricultural chemist, who cannot specially provide all the expen- 
sive arrangements and command all the assistance necessary to 
render chemico-physiological experiments applied to agriculture 
thoroughly satisfactory. A further difficulty arises from the fact 
that the same description of food which is assimilated in a great 
measure by one kintl of animal often remains to a much greater 
