200 The Vegetable Individual in its relation to Species. 
tion is not predetermined by the leaves. Originating at a later 
period, they take their rise not from the surface but from the cam- 
bium layer,—the internal tissue which preserves the faculty of 
producing new growths. Hence if they would come to the light 
of day they must break through the bark. Their origin has been 
particularly described by Trécul.* W. Hofmeister, however, as 
I have already remarked, succeeded in tracing it in Equisetum 
back to the first cell, a cell in the interior of the stem. As is the 
case with axillary buds, such adventitious buds sometimes remain 
undeveloped for a long time (ten years and more) without losing 
their vital activity; a fact to which attention has lat tely been 
called by C. Schimper,t in a report on exostoses. When this is 
the case they not id he lnm develop into spherical or conical. 
wood-kernels, which continue to exist without any connexion 
with the ligneous body of the maternal stem ; this is especially the 
case in Beeches and Poplars. 
out of places where they do not usually appear. ‘There are 
shoots from the stem, the root and the leaves. In herbaceous 
stems they appear in situations determined by the leaves (in the 
axils of the leaves), while they may be found anywhere on 
old woody stemst as adventitious buds, or on any part of the lig- 
nified roots of most di icotyledonous woody growths, apd even 
n some monocotyledonous ones, as in umbraculifere.§ Shoots 
‘appear less frequently on the roots of herbaceous plants.|| Shoot 
formation from leaves has often been discussed and described in 
regard to many plants, especially Bryophyllum, nai ne pra- 
_tensis, Drosera, Malazis paludosa the A fine example of this 
-is shown by a Chelidonium ma ius ar. heeinaiadians reared by 
Bernhardi in the Botanical Garden at en from whose leaves 
* Trécul: Recherches sur (orig. des bourg. adv. Ann. des sc. nat., viii, (1847) P- 
268. 
+ In Sept., 1852, in the Versammlung der es > Wiesbaden. 
rely seat tered shoots appear on the herbace especially 0 the first 
internode under the cotyledons, as ee sme Tuphor’ 7524) first showed inde 
phorbia, and Bernhardi f Lina specim Begon 
dipetala iadsianbed in our [Berlin] Boterent ‘Gaodag which i is pro bly the same 
boa as the B. phyllomaniaen of Martins, wrnee the case of a plant which DY 
oa a roultitude of shootlets in the whole Neat on; rtd rise from the 
which is not yet ha Sdened: 4 soon after th of the 
5 Atiadke to Rheede, Corp aphe Redan ie sends forth b routshooks when the 
stem dies off a the Se has ripened, 
ji ve often observed them in Tinsits vulgaris, Helichrysum arenarium, Rumes 
cetosella, sedis Jurinea Pollichii, Nasturtium sylvestre et Pyrenaicum 
‘According to ydler, they often appear in Viola sylvatica, 
