123 Mr. A. Ilenfrey on the Progress of Physiological Botany : 



Labiata ; but the author states that this is incorrect, inasmuch as 

 these latter are the commencement of the central ligneous sy- 

 stem, being in fact afterwards united together into a ring by new 

 bundles which are produced between them. 



The author says he formerly imagined these secondary wood 

 masses to have the import of branches, bat he has now given up 

 this opinion, having found the structure to be normal in several 

 other instances. In trees with opposite leaves, like the ash and 

 horse-chestnut, the woody mass presents the following pecu- 

 liarities in the youngest internode : the vascular bundles from 

 each petiole, arranged in a semicircle, unite with those of its 

 fellow to form a circular or rather somewhat quadrangular mass ; 

 at the next node below, this opens on opposite sides to receive the 

 bundles of the petioles there situated, and again closes. In Ca- 

 lycanthus the fibrous substance of the petiole also forms a semi- 

 circle, containing the vascular bundles of all the nerves of the 

 leaf except that of the lowest or outermost nerve on each side, 

 which remains isolated. This isolation is persistent after the 

 two semicircular fibrous bodies have united at the node to form a 

 ring, and thus it happens that the bark of the new-formed stem 

 contains four smaller vascular bodies, outside the regular ring of 

 wood and occupying the four obtuse angles. Tracing the course 

 downward in the stem, we find, at every node, that not only the 

 central ring, but the cortical woody bodies receive accessions, and 

 they have grown independently. In Calycanthus floridus there- 

 fore (and in C. pracox also, although it is not so distinctly ex- 

 hibited here), the four cortical ligneous bodies originate in the 

 leaf, run down in the angles of the gutter-shaped petiole, distinct 

 from the central mass, and enter the bark at the nodes, where 

 each of them unites with one similar coming down from the leaf 

 above and another coming from the leaf opposite. This obser- 

 vation has already been made, substantially at least, by Gaudi- 

 chaud, but was doubted, without statement of the reason, by 

 Lindley. Any one may readily satisfy himself of its correctness 

 who will examine this common shrub. [I found the above de- 

 scription of the structure perfectly correct as regards C. floridus ; 

 I have not examined C. pracox. — Rep.*^\ 



The woody stems of certain climbing Sapindacece are still 

 more remarkable on account of the number and size of the late- 

 ral woody masses ; sometimes as many as ten of these occur, in- 

 closed in a common bark, and these rapidly increase in size to 



* The arrangement of the woody bundles of the Cucitrbitacece which have 

 pentagonal stems, described by Dr. Stocks in the ' Ann. of Nat. Hist.' for 

 Aug. 1846, bears some relation to this point. It would be interesting to 

 ascertain whether any of them remain distinct, or if they become blended as 

 in the Labialce. — Rep. 



