78 The Botanical Gazette. [February, 
nium neck anc projecting antheridia of the Leptosporangiate are 
secondary developments.—DoucLas HoucHTon CAMPBELL, Serlin, 
Germany. 
Botanical notes (wITH PLATE viI).—I. The spreading of raspberry 
bushes by a system of natural “layering.” Rubus occidentalis.—A few 
observations, apparently not hitherto recorded, gave rise to the follow- 
ing more complete account of a process, the more general facts of 
which were already well known. The internodes formed by the rasp- 
berry in later summer are considerably longer than those produced 
earlier in the season, and bear but few prickles. This later growth 
becomes recurved and seeks the ground, the newer internodes being 
very long. After the stem has developed to a certain length in this 
downward direction, the newer internodes are very rapidly shortened, 
and the prickles become very numerous as compared with their fre- 
quency elsewhere on the stem. It was very interesting to see that 
when the plant grew on the sides of cliffs this shortening of internodes 
took place, even when the ground had not been reached, and when 
the growing ends of the descending branches were fully illuminated 
by the sun. The habit of terminating the branches at a certain length 
by means of the shortened internodes covered with prickles seems t0 
have become so strong that the branches go through the process even 
where, owing to their growth on the side of cliffs, the normal condi- 
tions, which must have given origin to this habit—the shade and damp- 
ness formed by leaves along the ground, and the presence of loose 
earth into which the branches could penetrate—do not exist. The 
prickles towards the tips of the branches are strongly curved back- 
wards, in decided contrast to the ordinary prickles of the plant which 
are fairly straight, and are placed nearly at right angles to the stem. 
On reaching the ground the shortened internodes curve forwards and 
enter it obliquely. The recurved prickles prevent the tips which are 
just starting root from being readily torn out of the ground, catching 
hold of the underbrush and weeds among which they have rooted, 
and hooking into the ground itself. 
As the joints began to lengthen during summer, the leaves greW 
smaller, and by the time the newer internodes were strongly short 
ened, preparatory to rooting, the leaves were reduced to small scales, 
subtending small scaly buds. Indeed, this reduction to scales takes 
place even in the open air, before the ground has been reached, but 
is universal on the rooting part of the stem. 
owards the tip of the branches, among the shortened internodes, 
the stem sends out rootlets. These do not come out at any point 0 
the stem, but occur in two pairs, at each node, just below the base of 
\ 
