NEW FEATURES IN CALAMITES AND EQUISETACEÆ, 283 
tions of this are found in Equisetum. In Eucalamites, where short internodes 
with branches are successive, there is a modification of the features met with 
in the other subgenera*. The following measurements of specimens of 
Equisetum arvense, L., collected at Lowesby, Leicestershire, on May 15th, 
1908, serve to indicate how fertile stems exhibit these characters :— 
TABLE III. 
Inter- | | | | 
een IZ ШЕ ше ppm ii | 
| | | EI Se 
A 5 |15|2 22 27 | 95 | .. |.. | 15em 
В ........ 5 15 25 | 3 88 | 3.8 .. .. 18 cm. 
С... 8 15|2 25 028 32 | 25 | 21 | 30cm. 
D ........ ()5 | 14 | 2 | 9 29 3 з |. 16:5 em. 
E ........ 5 | 15| 19, 24 8 38 | 34 | .. | 195cm 
Foo, 5 (15 22,3 | 38 | 82). |... | 105en. 
The uniformity in the length of leaf-sheath also is further illustrated т 
the subjoined table :— 
TABLE IV. 
seda, ШЕ ШЕ D (Debe he be Gil 
А........ 1 1 18 l4 INS 
В ........ 18 1 1:3 15 1:6 
Ст ........ Ke 8 1 1 1 12 13 | 15 16 | 16+ 
D ........ 7 `8 11 13 16 16 
Ep. 6| 7| 9|1 12 | 14 | 16 | 19 
Е ........ T 1 1:2 14 1'6 18 
In the two foregoing tables tho first internode is remarkably uniform, *5 cm. 
(or in one case '8 em.). In D, where it is doubtful, basal leaf-sheaths overlap. 
* In all three subgenera the strength-imparting function may reasonably be predicated as 
explanatory of the position of the short internode. 
+ The first three leaf-sheaths overlap. | Owing to this the measurements where indicated 
[ The first two leaf-sheaths overlap. are somewhat uncertain, 
