Index . 
xi 
Figures. 
PAGE 
1. Diagrams showing the development of the extra-marginal type of pinna- 
supply in Dryopteris vivipara (Raddi), C. Chr. (Davie) . .234 
2. Ditto to illustrate the development of the marginal type of pinna- 
supply in Pteris umbrosa, R. Br. (Davie) ..... 234 
3. Ditto showing the extra-marginal type of pinna-supply, with a i rein¬ 
forcement ’ derived from the abaxial curve of the leaf-trace, in 
Cibotium barometz (L.), J. Sm. (Davie) ..... 235 
4. Ditto illustrating the marginal type of pinna-supply, with a * reinforce¬ 
ment ’ derived from the abaxial curve of the leaf-trace, in Lonchitis 
pubescens, Willd. (Davie) ..235 
5. Ditto illustrating the extra-marginal type of pinna-supply, with a 
£ reinforcement ’ derived from the abaxial curve of the leaf-trace, in 
Dryopteris grandis (Pr.), C. Chr. (Davie) . . . . .236 
1. Average dry weights of ten series of pea plants grown in strong 
nutrient solutions in the presence of differing amounts of phenol 
(Brenchley) . .260 
2. Ditto grown in weak nutrient solutions (Brenchley) . . . 260 
3. Average dry weights of ten series of barley plants grown in strong nutrient 
solutions in the presence of differing amounts of phenol. Solutions 
never changed (Brenchley) . . . . . . .262 
4. Ditto. Solutions changed every three weeks (Brenchley) . . 263 
5. Ditto. Solutions changed every two weeks (Brenchley) . . 263 
6. Average dry weights of ten series of pea plants grown in strong 
nutrients in the presence of differing amounts of 0-cresol 
(Brenchley) ...... ... 265 
7. Ditto in presence of /^-cresol (Brenchley) ..... 265 
8. Ditto of/-cresol (Brenchley).265 
9. Average dry weights of ten series of barley plants grown in strong 
nutrients in the presence of differing amounts of <?-cresol 
(Brenchley) . .. 268 
10. Ditto in presence of w-cresol (Brenchley).268 
11. Ditto of/>-cresol (Brenchley).269 
12. Average dry weights of ten series of pea plants grown in strong nutrient 
solutions in the presence of differing amounts of resorcinol 
(Brenchley) ..271 
13. Ditto of ten series of barley plants grown in the same (Brenchley) 271 
14. Average dry weights of ten series of pea plants grown in strong 
nutrients in the presence of differing amounts of pyrocatechol 
(Brenchley).27 2 
15. Ditto in presence of pyrogallol (Brenchley) . . . . . 273 
16. Ditto of phlocoglucin (Brenchley) . . . . . . 274 
17. Ditto of orcinol (Brenchley) . . . . . . . . 274 
18. Average dry weights of ten series of barley plants grown in strong 
nutrient solutions in the presence of differing amounts of orcinol 
(Brenchley).275 
I. 1. Embryo sac mother-cell in homotype division. 2. Tetrad; both 
micropylar and chalazal megaspores showing further growth. 
3. Two middle megaspores show signs of disentegration. 4. Micro¬ 
pylar megaspore disentegrating. 5. Chalazal megaspore disinte¬ 
grating, while the micropylar one is developing still further. 
6. Chalazal megaspore in binucleate stage, having disorganized 
sister spores on the upper end. 7. Developing micropylar megaspore 
with a large vacuole and two nuclei in the upper part. 8. Meta¬ 
phase of the second division of megaspore nucleus. 9. Tetra- 
nucleate stage. 10. Immature embryo sac. 11. Mature embryo 
