* 
324 BOTANICAL GAZETTE [NOVEMBER 
resin canal can be seen making its way outward through all the 
annual rings seen in the plane of the figure. By careful inspection 
it is also possible to make out that there are vertical canals in series 
in the spring wood of the first ring of ligneous growth subsequent to 
injury. Fig. 5 shows part of another section through the same 
wound more highly magnified. The tangential series of resin canals 
in the spring growth of the first traumatic ring can now be clearly 
seen. Passing off from these can be made out three horizontal ducts, 
the most median of which does not actually communicate with the 
vertical canals in the plane of the present section. To the right of 
the figure a short tangential series of ducts can be seen in the second 
ring of growth formed after the wound. No horizontal canals 
originate from this weaker series of vertical canals. Fig. 6 is taken 
from the center of the wounded region, and the annual rings imme- 
diately abutting on the wound are the second and third formed 
subsequent to the injury. Each of them contains a weak series of 
vertical canals in the vernal wood, but these do not give rise to aly 
horizontal ducts. Fig. 7 shows a part of another section through 
the same wound, somewhat more highly magnified. The vertical 
canals of the spring wood are now clearly discernible, and from these 
are passing off in the horizontal direction three huge resin canals. 
Two of these are more or less completely filled by parenchymatous 
tyloses. ical and 
We are now in the position to discuss the resin canals se a 
a 
horizontal appearing in figs. r and 3. It is a well-known iia 
in the Abietineae the formation of resin canals -— : “i 
about as the result of wounds. The present writer has sho 
the same feature is found in the living species of Sequoia.* bet 
existing species of Sequoia the formation of traumatic resin ¢ gf 
entirely confined to the vertical plane, so far as our present marie 
goes. In those Abietineae which give rise to ligneous eS . except 
as a result of injury they are also confined to the vertical plane, 
in the genus Cedrus, where, as the present author shows ees Three 
about to be published, they are formed horizontally age nt under 
cases of injury have been found in the fossil Sequoia - ee to the 
consideration, and in each of the three cases the injurie » no. 10° 
3 Jerrrey, E. C., Memoirs of the Boston Society of Natural — 
