REVERSIONARY CHARACTERS OF TRAUMATIC OAK 
WOODS 
Irvinc W. BAILEY 
(WITH PLATES XI AND XII) 
» Instudying the phylogeny of plants there are certain principles 
or canons of comparative anatomy which have been formulated 
within recent years by morphologists and anatomists. Thus the 
application, to seedling plants, of HAECKEL’s law of recapitulation 
for stages in ontogenesis has been strikingly illustrated by STRAS- 
BURGER, GOEBEL, JEFFREY, EAmes, and others. Furthermore, 
the persistency of ancestral characters in certain regions of plants 
has been well established. In this connection the researches of 
Sorms-LauBAcH, Scott, and JEFFREY have shown conclusively 
that the cone axis is often the seat of primitive characters. The 
importance of foliar organs in connection with ancestral characters 
has been shown by Scorr, JEFFREY, and Favit. JEFFREY has 
further pointed out in his memoir on Sequoia? the importance of 
vigorous cone-bearing branches of Sequoia gigantea as the seat of 
recapitulation of ancestral conditions. The importance of hyper- 
trophied or wounded areas as the seat of reversion to primitive 
characters is strongly appreciated by zoologists. This principle 
has also been applied to the traumatic areas of plants by JEFFREY, 
who has pointed out the traumatic reversionary origin of resin 
canals in the wood of the higher Abietineae,? certain Sequoiineae,* 
and the older Araucarineae,s which normally possess none of these 
* Contributions from the Phanerogamic Laboratories of Harvard University, 
no, 24. 
*The comparative anatomy and phylogeny of the Coniferales. I. The genus 
Sequoia. Mem. Boston Soc. Nat. Hist. 5:441-459. pls. 68-71. 1903 
3 The cco anatomy and a * — IT. The Abietin- 
eae. Mem. Boston Soc. Nat. Hist. 6:1 
4 The ORE ——. and pe eny . the ie. J. The genus 
Sequoia. Mem. Boston Soc. Nat. Hist. 5:441-459. pls. 68-71. 1903- 
Pee wound reactions of Brachyphyllum. Annals of Botany 20:383-394 P!S- 
=. prenaen) a new genus of araucarians. Bor. GAZETTE 44:435-444 pls. 
28-30. 1907. : 
Botanical Gazette, vol. 50] (374 
