Index . 
Vll 
b. Figures. 
3. Ditto of old branched root (Jackson) 
13 
4,5- 
6 . 
7 , 8 . 
9- 
10. 
11. 
12. 
r 5- 
2-4. 
5- 
6 . 
3-11. 
2. 
3* 
4- 
5- 
6 . 
7- 
1-12. 
1-6. 
Transverse section of root through point of emergence of lateral a (branched 
type). 5. Ditto of lateral b (branched type) (Jackson) 
Part of a transverse section of a young ‘ unbranched ’ root (Jackson) 
7. Ditto of an intermediate ‘ unbranched ’ root. 8. Ditto of an old ‘ unbranched ’ 
root (Jackson) 
Ditto of an ‘ unbranched’ root, showing an undeveloped lateral (Jackson) . 
Ditto of a ‘ transition ’ root (taken near grain) (Jackson) . 
Ditto (taken near root-tip) (Jackson) 
Diagrams showing stelar structure of the different types of roots (Jackson) . 
13. Single cell of mucilage tissue, with walls fully extended with water. 14 a and 
143. Single microsporophyll removed from dry mass of bases and sporangia 
found on surface of soil in June. 1 5. Sporangium wall in surface view, after it 
has torn away from sporophyll, showing fimbriated segments into which side of 
wall has torn (Osborn) . . . . 
Subterranean portion of a plant of Isoetes Drummondii collected towards the close 
of the growing season (Osborn) ......... 
2. Plant collected at the opening of the vegetative season. 3. Plant collected in 
June at the stage of elevating the old sporophylls. 4. Dry projectile-like mass 
of imbricate sporophyll bases, collected on surface of soil in June (Osborn) 
A single ‘ cap ’ or desquamated stock lobe, a, the leaf-bearing surface, b, the root- 
bearing surface, c, the distal ‘ scar ’ surface (Osborn) ..... 
a, b , and c. Series of vertical sections of stocks at different seasons cut in plane 
of one lobe and groove (Osborn) 
Diagram to explain state of stock, as seen from below, at close of vegetative season 
(Osborn) 
8. Cells from mucilage tissue at base of sporophyll collected in October. 9. Micro- 
sporophyll in transverse section. 10. Megasporophyll viewed abaxially (10 a ) 
and laterally (10 b), showing pad of mucilage cells extending across base, also 
extent of tough ‘ shield ’ developed behind sporangium. 1 1. Median longitudinal 
section of megasporophyll collected in October (Osborn) . . 
a, ripe sporangium wall in surface view, showing irregular arrangement of cells on 
flat upper surface and regular shape of cells of side-walls, b, cells in side-wall 
of ripe sporangium, c, transverse section of ripe sporangium wall, showing cells 
somewhat distended with water and stout cuticle (Osborn) .... 
Exosmosis of Nutrient Substances from the Host Tissue into the Infection Drop 
(Brown) 
Flowering Curves of the Egyptian Cotton-plant (Prescott) 
page 
25 
26 
28 
Abnormal Flowers in Eranthis (Turrill) . . 
1. Matthiola incana, seedling showing glabrous cotyledons and hypocotyl and 
hairy plumule. 2. Older stage. 3. Veronica hederaefolia, seedling ; hypocotyl 
with a line of hairs along the potential edges of the cotyledon extensions. 
4. Lopezia coronata, seedling plant ; hypocotyl and internodes showing the 
same feature. 5. Ipomoea sanguinea, young seedling. 6. Older stage of the same 
(Saunders) 
7. Ruellia amoena, hypocotyl in transverse section ; the potential edges of the 
cotyledon extensions are thrown up into a ridge surmounted by hairs 8. Pinus 
maritima, hypocotyl (after Chauveaud). 9. Rivina humilis, hypocotyl showing 
the same features as Ruellia but without the hairs. 10. Stellaria media, 
internode in transverse section (Saunders) 
29 
30 
31 
3 2 
35 
52 
4 2 
43 
45 
46 
48' 
49 
5i 
104 
121 
122 
123 
1 24 
12 5 
126 
127 
132 
136 
137 
