Anomalous Forms of Dicotyledonous Stems, 127 
such an extent, that they often, collectively, exceed in volume the 
central ligneous mass of the stem. No other plants but the 
Sapindacea are known with certainty to possess this structure, 
and not even all the genera of this family, nor all the species of 
particular genera. Gaudichaud does not name the species and 
only doubtfully the genus in which he found it ; A. de Jussieu* 
names only Serjania cuspidata. The author has detected it in 
Paullinia pinnata, Serjania triternata, AV., and Serjania Sello- 
viana, Kl., but not in Serjania ruhifolia, K., and Paullinia obli- 
qua, K. ; not in Cardiospermum, Nephelium, Kodreutera, Sapin- 
dus saponaria and capensis. He had at his disposal a living stem 
of Paullinia pinnata^ bearing leaves, the length from ten to twelve 
feet, and the thickest portion a German inch in diameter. This 
stem presented three convex sides and as many obtuse angles in 
each of which lay a woody mass unconnected with the central 
mass and separated from it by cortical substance ; they were of 
similar form and almost identical structure. In Serjania triter- 
nata the stem in the young shoots is triangular with a woody 
mass in each angle, but in the older twigs the angles and their 
lateral woody masses are seven in number, and the same struc- 
tm-e occurs in S. Selloviana, KL, so that it may be concluded 
with tolerable certainty that the woody bodies which Gaudichaud f 
indicated generally as belonging to Sapindacece were either spe- 
cies of Paullinia or Serjania. The same may be said of a form 
of wood from an unknown source described and figured by the 
author in his ^ Physiology of Plants The number of lateral 
masses may as above shown increase, but it may also decrease by 
some of them losing their independence. In one of Gaudi- 
chaud^s§ plates the upper end of one specimen exhibits nine, 
the lower only five, another seven above and five below ; so that 
some of them have either become united together or to the cen- 
tral body. Jussieu says : the four woody masses of Serjania cus- 
pidata, at the first formation of a shoot, are united into a single 
mass ; but they soon separate and become isolated. The author 
also, in the twigs of Paullinia pinnata, where they run out as side 
shoots from the triangular main stem, perceived that the form 
was originally cylindrical, and thus only a central woody mass 
existed, but that in its course one or more lateral bodies disen- 
gaged themselves. The manner in which this took place is thus 
explained : the circle formed by the aggregated bundles presents 
three obtuse angles, and the bundles which form these angles 
diverge outward and leave the combination. They then become 
* Monogr. Malpigh. — Archiv du Mus. iii. 110, 117. 
t Rech. sur TOiganogr. &c. des Veg. t. 13. fig. 1-4. t. 18. fi.gs. 14, 16, 
18, 19, 21. 
X Phys. d. Gew. ii. 174. t. 1. fig. 6. 
§ Loc. cit. t. 18. figs. 16, 19. 
