Index . 
IX 
Figures. page 
3. A, B, Two young antheridia; B shows a regular octant division; c, three somewhat 
older antheridia ; D, three young antheridia in cross-section ; E, F, older antheri- 
dia ; G, cross-section of stalk of mature antheridium (Campbell) ... 6 
4. A-H, Development of the archegonium. c shows a very young archegonium close 
to an older one (Campbell) 8 
5. a, Surface view of the neck of an older archegonium, showing the torsion of 
the neck-cells ; B, cross-section of the archegonium neck, showing four 
peripheral cells ; c, venter of a ripe archegonium ; d, venter of an archegonium 
in which the ventral canal- cell and the egg-cell are enclosed in a thick membrane ; 
e, apex of the neck, seen from the surface ; F, three cross-sections of a young 
archegonium — 1, 2, near the base; 3, the neck ; G, an archegonium, with four 
neck canal-cells, in which no cap-cell had been formed ; H, apex of an abnormal 
archegonium, suggesting an antheridium (Campbell) 9 
6. a, Two sections of a young embryo ; B, an older embryo, enclosed in the calyptra, 
cal. ; c, apex of the embryo, shown in B ; D, upper part of calyptra, and young 
sporophyte ; E, longitudinal section of young sporophyte ; F, the foot ; G, young 
spore mother-cells and elater ; H, two young spore-tetrads ; only one nucleus 
in each tetrad is normal (Campbell) i o 
1. Graphs showing comparative rates of transpiration of two plants of Pelargonium 
(Bergman) 18 
2. Comparative transpiration of two seedlings of Quercus macrocarpa (Bergman) . 19 
3. Comparative rates of transpiration of seedlings of Quercus macrocarpa in moist and 
in submerged soil (Bergman) 20 
1. Bumilleria exilis, Klebs (Bristol) 48 
2. Ankistrodesmus falcatus, (Corda) Ralfs, forma terrestris (Bristol) ... 49 
3. Germination of spores of some Myxophyceae. A, Nodularia Harveyana, (Thwaites) 
Thuret. B, Anabaena oscillarioides, Bory, forma, c, Anabaena sphaerica, 
Born, et Flah. D, Cylindrospermum licheniforme, (Bory) Kuetz. e, Nostoc 
sphaeroides, Kuetz. f, Nostoc muscorum, Kuetz. (Bristol) .... 50 
4. Nostoc commune, Vaucher, from arable soil, Tisbury, Wilts. (Bristol) . . 52 
5. Tribonema bombycinum, (Ag.) Derb. and Sol. (Bristol) 53 
6. Nostoc minutum, Desmaz. (Bristol) 62 
7. A, Cylindrospermum marchicum, Lemm., forma tenue,n.f. B, C. muscicola, Kuetz. 
(Bristol) 64 
8. Soil-diatoms I (Bristol) ... 66 
9. Soil-diatoms II (Bristol) 69 
10. Soil-diatoms III (Bristol) 71 
11. 1-7, Chlamydomonas communis, Snow ; 8-14, C. pluristigma, n. sp. (Bristol) . 73 
12. Ulothrix tenuissima, Kuetz. (Bristol) 76 
1-3. 1. a-g. Hemitricotylous seedlings showing various stages in the division of the ab- 
normal cotyledon. 2. a-c. Hemitricotyl type a. 3. a-d. Hemitricotyl type /3 
(Bexon) 83 
4. a-e. Hemitricotyl in which the bundle supplying one lobe of the abnormal 
cotyledon retains its collateral structure (Bexon) 85 
5, 6. 5. 1, 2 a and b, 3 a and b. Hemitetracotylous seedlings. Seedling 2 a and b is 
a 1 twin ’ showing double structure. 6. a-e. Hemitetracotyl B. Diagrams 
illustrating double structure of ‘ twin ’ seedling (Bexon) 87 
7. a-f. Hemitetracotyl D (Bexon) 88 
8. a-f. Hemitetracotyl C (Bexon) 89 
9. Syncotylous seedlings (Bexon) 90 
1 -1 5. Uronema indicum, sp. n. (Ghose) ......... 97 
Transverse section of rhizome of Cordyline Shepherdii with an emerging root. 
Diagrammatized (Spratt) 101 
1,2. Variation curves for Anemone hepatica, A. nemorosa, A. apennina, and inner 
perianth of Ranunculus bulbosus (Salisbury) ....... 108 
3, 4. Ditto for androecium and gynaeceum of A. apennina (Salisbury). . . . 109 
