SnLlAKtm] PROCEEDINGS OF SOCIETIES. 219 



aberrant forms of dicotyledonous stems, but I shall bere notice only- 

 two wbicb are met with on cotton bales. 



One of tbese is most probably the Serjania cuspidata figured by 

 Duchartre* and Schleiden,f and easily recognized by its triangular 

 form and compound character. It consists of a primitive stem not 

 sj)ecially noticeable for any divergence from the usual type of a 

 dicotyledonous stem ; but round this stem are arranged thi'ee other 

 lateral stems, each of which has its own bark separate from the rest, 

 but united to the bark of the primitive central stem. These lateral 

 portions are circular in outline, save that they are flat on the side by 

 which they are attached to the central stem, which latter is in conse- 

 quence hexagonal. The attachment of the lateral portions to the 

 central mass is not very firm, as most of the rojies of this species reach 

 this country with their strands separated, but this is due to the rough 

 usage to which they have been subject in packing ; but Gaudichaud 

 points out that in certain parts of the stem — most likely at the nodes, 

 for he is not very clear upon the point — the lateral strands have an 

 organic attachment to each other, since some of the woody fibres of 

 the central mass are continued in one of the lateral strands, and vice 

 versa. \ 



A still more remarkable example suj^plied by this family in the 

 form of a natural rope, is one which might have served our telegraph 

 engineers as the model of a submarine cable. Like the Serjania, there 

 is a central woody mass possessing a medullary sheath and pith, woody 

 layers, and a cortical system ; but surrounding this central core and 

 arranged 2:)arallel with it is a series of eight lateral strands, each sur- 

 roimded by its own bark, the whole being consolidated so as to form 

 a rigid cylindrical axis, which presents no external manifestation of its 

 peculiar internal organization. It is represented in the last figm'e of 

 Gaudichaud's ' Kecherches,' § and has been copied into most of our 

 text-books, in some cases incorrectly described as a Maljnghiaceous 

 plant, as by Professor Balfour in his ' Class Book,' figs. 186 and 

 1429. 



On examining such stems of this order as I have been able, the 

 pith and medullary sheath with its characteristic tracheal vessels 

 appear to be met with in the central mass only, and some botanists, 

 contrary to the opinion expressed by Jussieu,|| doubt the existence of 

 these organs in the lateral strands. Nevertheless, one of the most 

 recent observers of these stems, Herr Nageli, has recently demon- 

 strated their presence in each of the siu'rounding woody masses.^ 



A short summary of their mode of growth, communicated to the 

 French Academy by Monsieur Netto, will be found in ' Comptes Een- 

 .dus,' t. Ivii., pp. 554-557, 21 Sej)t., 1863, from which it would appear 

 that a young stem, two to three weeks old, exhibits a number of fibro- 

 vascular bundles in the midst of an outer zone of cellular tissue, one 

 bundle being formed opposite the innermost portion of each of the 



* ' Elements,' &c., fig. 82, p. 170. t ' Principles,' fig. 168, p. 253. 



X ' Eecherches,' pi. xiii., figs. 2 and 3, p. 110. 



§ PL xviii., fig. 21, p. 130. || ' Memoire,' pp. 116, 117. 



^ Dickeuwachsthiim des Stengels . . . bci den Sapiudaceen. Munich, 1864. 



