JEFFREY. — ARAUCARIOXYLON TYPE. 553 



men of Brachyoxylon. On the loft appears the wojind parenehyma, 

 which universally adjoins a wound in woody tissues. To the right 

 of this appear certain somewhat compressed cavities in the wood, 

 surrounded by cells filled with dark contents. The cavities in ques- 

 tion are the traumatic resin canals, which are a feature of the Brachy- 

 oxylon type. Figure b, Plate 7, from the same sfx'cimen shows part 

 of a row of traumatic resin canals farther away from the same wound. 

 It is an interesting fact in woods, in which resin canals are either 

 almost obsolete or may be recalled only by experimental means, that 

 they occur in nearly continuous tangential rows. This for example 

 is the case with the resin canals in the woods of species of the genus 

 Sequoia and Avith the woods of the genera Abies, Cedrus, Tsuga and 

 Pseudolarix of the Abieteae, which are admitted by those who have 

 recently flevoted special attention to the comparative anatomy of the 

 Coniferales, to be descended from ancestors which possessed resin- 

 canals abundantly and normally in their woods. It follows that the 

 presence of traumatic resin-canals in close tangential rows in the genus 

 Brachyoxylon is prima facie evidence that this t^^pe has come from an 

 ancestry which possessed normal ligneous resin canals. This con- 

 sideration alone enormously complicates the task of those who endeavor 

 to derive the Abietineae from Araucarian ancestors, for they have to 

 explain the presence of resin-canals in an obsolete and vestigial con- 

 dition in forms, which they claim to be the direct ancestors of the 

 pine-like Abietineae, in which the resin canals are highly developed. 

 It is scarcely necessary to point out that this is a palpable logical con- 

 tradiction. It is unnecessary to figure the longitudinal view of the 

 traumatic resin canals in the wood of the Brachyoxylon type of Arau- 

 carian woods, since this subject has already been sufficiently dealt 

 with in the articles by the present author cited above. It is well 

 however to point out at this stage that Brachyoxylon has the type of 

 ray which is characteristic of living representatives of the Araucarian 

 stock, namely one in which the cells are without pits and thin walled, 

 except where they are laterally in contact with the tracheids of the 

 wood. The pitting in this type is often strikingly Araucarian and at 

 the same time in many instances the radial pores are widely spaced. 

 In no case is there any indication of the presence of cellulose l)ars of 

 Sanio, although many of the specimens, which have passed under 

 my notice are in a remarkable condition of preservation, which has 

 been a matter of comment on the part of all who have examined 

 them. 



Figure c, Plate 7, illustrates part of a transverse section of Arau- 



