506 



BOTANICAL GAZETTE 



[DECEMBER 



oooo 



difficulty might be increased by the presence of cutin on the walls 

 of the diaphragm cells, but the walls of these cells in Scirpus 



validus give the cellulose 

 reaction only. 



Sauvageau (27) 



found that after inject- 

 ing the stem with water, 

 some of the canals were 

 suberized, and con- 

 cluded that suberization 

 takes place after contact 

 with water, to prevent 

 a few cells from infiltration of the sur- 



Fig. 8. 

 cross-section 



■Scirpus validus: 

 of leaf 



of young bud: epidermis, 

 parenchyma, and spongy tissue of air space shown; 



rounding tissues. As he 



section treated with Fehling's solution; strong re- offers no direct proof of 



action indicated by stippling (s) ; merely size, posi- 

 tion, and shape of cells indicated; X175. 



suberization following 

 contact with water, defi- 



nite conclusions cannot be derived 

 from this work. 



C. TO AID IN CIRCULATION OF AIR 



Haberlandt ( 



amon 



of 



ragms. It seems evident 



geous 



that, given partitions, it is advanta- 



to have them perforated, to 

 allow circulation of air. The state- 

 ment made by Goebel (13) that non- 

 perforated diaphragms in Pontederia 

 crassipes (Eichhornia) allow circula- 

 tion of air needs proof. 



D. NUTRITION 



Le Blanc (17) supports Chatin 1 



Fig. 9. — Scirpus validus: a few 

 cells from cross-section of leaf of 

 young bud: treated with Fehling's 

 solution, I in KI, and K 2 Cr 2 7 ; c, 

 cell showing cytoplasm and scat- 

 tered starch grains; ct, cell with 

 contents plasmolyzed, starch 

 grains not distinguishable; st, cell 

 which has reduced Fehling's solu- 

 tion and given tannin test with 



in believing nutrition to be one of K 2 Cr 2 7 ; X175. 



1 Chatin, Adolphe, Anatomie comparee des vegeteaux. Paris. 1856-1862. I 

 have not been able to obtain this publication. 



