28 BULLETIN 1450, U. S. DEPARTMENT OF AOP^ULTCT 
On March 21 it was observed that the roots of the innovations 
were making new growth, but the roots of the shoot wliieh grew in 
1913 showed no signs of life. 
From the observations which have been recorded it may be con- 
cluded that at least some of the roots of a timothy shoot may con- 
tinue to grow or function for several weeks or months after the 
upper part of the shoot has become dry, but by the following spring 
the roots on these shoots have usually all become lifeless. Timothy 
roots, then, are not perennial. The period of the lite ol all the roots 
of a shoot usually extends through part of one season and through 
part or all of the following season. Less frequently, on shoots which 
develop from seeds or buds in the spring, the period of growth of 
the roots of a shoot, like that of the shoot itself, may be limited to 
a single season. 
THE HAPLOCORM 
At the base of most elongated timothy shoots one, less frequently 
two, and occasionally three of the lowest elongated internodes become 
enlarged, x form the haplocorm. Typical haplocorms are shown in 
Plate 7, A and B. 
In one meadow which was examined in July, 1916, it was found 
that in a typical area of 1 square foot on 88.5 per cent of the 
elongated shoots the haplocorm was composed of a single internode, 
whereas on the other 11.5 per cent there were two enlarged inter- 
nodes. In another meadow, examined in October, 1917, it was found 
that in a typical area 85.7 per cent of all stubble of culms had one 
enlarged internode, and on the remaining ones there were two en- 
larged internodes. Occasionally a shoot has been found with a 
haplocorm consisting of three enlarged internodes. However, as 
indicated by these records and by other data, usually 75 to 90 per 
cent of the haplocorms in any timothy meadow are composed of one 
and nearly all of the others are composed of two enlarged internodes. 
A haplocorm is solid; in this respect, as well as in being shorter 
and having a greater diameter, it differs from the typical hollow 
cylindrical upper internodes of the culm. 
In the spring of 1916 a series of measurements was made of a 
group of 16 timothy shoots, each with a haplocorm composed of a 
single enlarged internode, which ranged from 0.3 to 1.4 inches in 
length; the average length was 0.66 inch. When there are two en- 
larged basal internodes each one is usually shorter than on shoots 
with one enlarged internode, so that the length of the haplocorm 
usually is not greatly different, whether it is composed of one or two 
internodes. 
The diameter, like the length of the haplocorm, varies in different 
timothy shoots; it is usually less than the length. The form of 
haplocorms also varies, as do the relative proportions of their 
lengths and diameters. 
The fact that the haplocorm develops between nodes from which 
leaves have grown indicates that it grows above the surface of the 
soil ; this is its normal position in shoots which have originated from 
buds on older shoots. Since the lower parts of timothy shoots often 
are more or less procumbent, the haplocorms grow in all positions 
