590 REMARKS ON INCREASE OF MUSCULAR FIBRE. 
is certain that no plants can be raised to perfection without 
the aid of vegetable mould. Plants growing in a rich soil 
must derive nourishment from it in some way ; for if removed 
to one less fertile, they decay, and often die quickly. Sap is 
ascending and descending; rises in the spring to the leaves, 
where it is elaborated, and undergoes some change, and 
descends to every part of the plant, becomes a part of the 
substance, and adds to the bulk. Sap is also changed at the 
first entrance by the vessels of the roots; for ingrafted plants 
can derive from the common stock the sap peculiar to itself. 
But what that sap, or food, or substance is, we have not been 
able to discover, owing to the minuteness of the rootlets, 
fibres, tubes, and pores, which almost escape detection by 
the microscope; and it may be very reasonably presumed to 
be in a state of solution as it ascends the organs in a liquid 
form. But in what way, or by what peculiar operation, the 
soil and manures yield the food in a liquid, or in any other 
form, and become so highly conducive to the growth of 
plants, is a point of very difficult research, and all the con¬ 
clusions yet formed on the subject must be regarded as 
matters of very doubtful speculation. Fortunately, the 
importance of being known seems much less than the difficulty 
of obtaining the knowledge ; for, if we were in possession of 
the latter as amply as could be wished, it is doubtful if any 
useful result would be derived, or if it would not rather remain 
a part of the ostentation of science, containing most beautiful 
scientific truths, but totally irreducible to practice. 
( To be coritinued.) 
REMARKS ON THE INCREASE OE MUSCULAR FIBRES. 
The muscular fibres of animal life, according to M. Budge, 
increase in number with age, and the development of muscles 
in bulk does not depend solely upon increase of size of the 
fibres. He gives the following figures to show the changes : 
size of the fibres of the gastrocnemius muscle of a frog— 
Frog of the length of 13*00 mil. 1053 fibres ; 17*00 mil. 
1727; 33*75 mil. 1925 ; 33*85 mil. 2271 ; 46*00 mil. 3434 ; 
80'00 mil. 571 1. Moreover he states that in a frog left with¬ 
out tood for three months and a half the number of the fibres 
were 3364, and that they were very fine; while in a like frog 
left in its normal state the number of fibres was 4462 and 
their structure normal. 
