

1917] . HUTCHINSON— KETELEERIA 133 



6. Leaves. — {1) The leaves are spirally arranged on ordinary 

 branches; (2) there are 2 very closely associated vascular strands 

 and 2 marginal resin ducts (15). 



7. Sieve tubes. — These present single interrupted rows of plate 

 groups on the radial and oblique terminal faces. Paired proto- 

 plasmic accumulations, one on either side of each plate, are con- 



. nected by strands which penetrate small perforations in the 

 intervening walls (figs. 6-8). The sieve tubes are more numerous 

 on the oblique terminal faces, an advance toward the angiosperm 

 condition. 



8. Cotyledonary tube. — This is significant in connection with 

 the theories of the origin of polycotyledony. 



The writer wishes to express his thanks to Professor J. M. 

 Coulter and Professor C. J. Chamberlain for material provided 

 and for advice and direction during the progress of the investigation. 



University of British Columbia 



LITERATURE CITED 



Gaz. 60:277-313. 1915. 



iporophylls of conifers. Bot. 



2. Coulter, J. M., and Chamberlain, C. J., Morphology of gymnosperms. 

 Chicago. 1910. 



3. Coulter, J. M., and Land, W. J. G., The origin of monocotyledony. 

 Bot. Gaz. 57:509-519. 1914 



4- -, ibid. Ann. Mo. Bot. Gard. 2:175-183. 1914. 



5. DeBary, A. (Bower, F. O., and Scott, D. II.), Comparative anatomy of 

 the phanerogams and ferns. 1884. 



6. Haberlaxdt, G. (Drummoxd, M.), Physiological plant anatomy. 



McMillian. 19 14. 



7 



mnosperms 



Ann. Botany 22:689-712. pi. 35. 1908 



8. . ibid. Ann. Botany 23: 189-227. pi. 15. 1909 



9. -, ibid. Ann 



10. , ibid. Ann 



1909 



11. Holden, R., Ray tracheids in the Coniferales. Bot 



pis. J, 2. 1913. 



Abies balsamm. Bot. 



figs 



13- , The male gametophyte of Pkea canadensis. Bot. Gaz. 59:287 



300. pis. 15-19- fig- *• 1915- 



