54 Puget Sound Marine Sta. Pub. Vol. 1, No. 8 



PLATE 9 



Fib. 21. Portion of lamina^ showing fistulose character of midrib. 



X0.4. 



Fig. 22. Lower end of stipe, showing tendency to send out well- 

 developed rhizoids from the sharply angled sides of the flattened stipe. 

 Those on the flattened sides are poorly developed. XO-S- 



Fig. 23. Portion of specialized sieve-tube area, showing sieve- 

 tubes surrounded by pith web and a mucilaginous substance. X272. 



Fig. 24. Cross section of sporophyll through a papillate, raised 

 portion of the surface. X272. 



Fig. 25. Branched sieve-tubes, or trumpet hyphae. \53. 



Fig. 26. Sieve-tube from specialized sieve-tube area of the midrib. 

 X53. 



Fig. 27. Unbranched sieve-tubes. X53. 



Fig. 28. Cross section of the lamina. X272. 



Fig. 29. Sieve-plate from specialized sieve-tube area of the midrib. 

 X520. 



Figs. 30-33. Pitted cells of cortex and outer medulla of stipe. 

 The arrows point toward the surface of the stipe. 



Fig. 30. Cortical cells near to medulla. X520. 



Fig. 3L Cell midway between outer and inner borders of cortex. 

 X520. 



Fig. 32. Cell of outer cortex. X520. 



Fig. 33. Cells at boundary line between cortex and medulla. The 

 cell with a central lumen shows sieve-tube being fiilled with callus. X520. 



