286 MR. A. В. HORWOOD ON CALAMITES SCHÜTZEI, AND 
Пс. Comparison between the position and function of the short internode 
in Calamites and recent Equiseta, and the rate of increase or 
decrease of internodes, ete., in both groups. 
Summarizing the foregoing facts for comparison, it is to be noticed that 
in fertile stems of Equisetum maximum and Е. arvense there is a gradual 
increase in the length of internode (and of leaf-sheath) up to the last but one, 
the last internode before a cone being shortened *, The smallest internode 
is at the base, or just below the cone. 
The converse is found in barren stems of Æ, maximum, the internodes 
decreasing. In Е. pratense the two modes alternate, a short node separating 
the two kinds of periods. The same is found in other species of Equisetum. 
Fertile stems of Equisetum arvense, Linn. 
(See Tables ITI. & IV. p. 283.) 
Thus in Equisetales (cf. short internode in C. Schiitzei, and at the base of the 
stem in C. Suckori?) shortened internodes occur at the base or between fertile 
* In some cases the terminal internode just before the cone is sometimes not shortened 
but the longest internode in the series in fertile stems of Equisetum arvense, Linn. This is 
owing to nature of soil or shade, 
