INTERCELLULAR CANALS IN DICOTYLEDONOUS WOODS 435 



A hand specimen of Escnbcckia fcbrifuga collected by Huber, of the 

 Museu Goeldi, Brazil, shows small canals in numerous tangential 

 rows — some very short, others continuous across the block. They are 

 presumably of traumatic origin and appear on the longitudinal surface 

 as narrow, inconspicuous lines, darker than the light-colored wood. 



Another specimen from the same source and labeled "tamanquiera" 

 contains numerous small canals in tangential series. Although the 

 name "tamanquiera" is applied by Huber to two woods, namely, Fagara 

 rhoifolia and Ocotca yiiyancnsis (Laurace^e), the structure corresponds 

 to that of the RutacCcC. It seems unlikely that canals would be found 

 in the woods of the Lauracese, although Hohnel (15, p. 166) reports 

 finding them in the wood rays of Oreodaphnc. Solereder (2, p. 704), 

 however, says Hohnel's statement "is without doubt incorrect," as is 

 also his report of finding secretory canals in the phloem rays extending 

 to the bark and presumably into the wood rays (although the latter 

 were not investigated) of Myrica sapida (Myricacese). 



Simarubacccc 



Two different specimens of the wood of Simaruba aniara from 

 Brazil contain numerous small canals closely arranged in tangential 

 series extending throughout the length of the specimens. In one of 

 the pieces there are several rows, some of which are only a few ducts 

 wide. They are filled with amber-colored material which exudes on 

 the white wood, producing distinct lines on the longitudinal surface. 



Biirseracece 



According to Tschirch (4, pp. 1202-3) the wood of Caiiariuiii coiii- 

 miine normally contains no secretory canals. In response to severe in- 

 jury of a stem under observation a tangential row of traumatic ducts 

 was formed in the inner portion of the new wood and embedded in a 

 broad zone of parenchyma, with scarcely any tracheidal-])arench\ma 

 present. The ducts originated schizogenously and enlarged lysige- 

 nously, showed the usual tangential network, but were not connected 

 witli the canals in the cortex. I'nless a wound is severe, no ducts in 

 formed in the wood, thfuigh resin pockets arise similar to th(xsc in conif- 

 erous woods. 



Mcliacccr 



Vertical canals of pathological formation ( gummosis ?) have been 

 observed by the writer in \arious s])ecimens of the wood of Swictcnia 



