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 

 Sapindacece 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, W., and Serjania Sello- 

 viana, Kl., but not in Serjania rubifolia, K., and Paullinia obli- 

 qua, K. ; not in Cardiospermum, Nephelium, Kalreutera, Sapin- 

 dus saponaria and capcnsis. 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- 

 ture 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 'J. 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 Recb. sur l'Organogr. &c. des Veg. t. 13. fig. 1-4. t. 18. figs. 14, 16, 

 18, 19, 21. 



% Phys. d. Gew. ii. 174. t. 1. fig. 6. § Loc. cit. t. 18. figs. 16, 19. 



