Vlll 
Index . 
Figures. 
i, 2. 
3 - 
4 > 5 - 
6 . 
7 * 
1, 2. 
3 - 
4 - 
5> 6. 
7, 8. 
A. 
I. 
/ 
PAGE 
the middle and is still elongating. 9. The fourth stage. The two daughter 
chromoblasts are now joined only by a thread. 10. The fifth stage. The two 
daughter chromoblasts have separated and have assumed the spherical form once 
more. 11. The sixth stage. The nuclear membrane has become more con¬ 
stricted and the whole nucleus longer. The chromatin on the membrane has 
regained its original density. 12. The two daughter nuclei are about to separate 
(Smith).69 
1. Botrytis cinerea on potato agar. 2. Alternaria grossularia on potato agar 
(Brown).112 
Fusarium sp. on potato agar (Brown) . . . . . . . . .113 
4. Sphaeropsis malorum on apple agar (deep and shallow) and potato agar (deep 
and shallow). 5. Fusarium sp. on apple agar (deep and shallow) (Brown) . 114 
Sphaeropsis malorum on potato agar (Brown) .. 115 
(Diagrammatic.) Vertical section of unstaled and staled colony (Brown) . -125 
1. Longitudinal section through the attaching base of Porphyra umbilicalis, showing 
the central rows of cells and the interwoven branching filaments. At A the 
proliferating portion is seen, and at B this portion is occupied by a colony of 
blue-green algae. 2. Outline drawings of the cells and filaments composing the 
disc of Porphyra. At A the first stage in the formation of the young filament is 
seen, showing the chromatophore and nucleus in the tip. B shows a second por¬ 
tion of chromatophore passing down. C, a disc cell producing two filaments. D, 
a disc cell with a cross-wall (Grubb) . . . . . . . .134 
Outline drawings showing the modifications undergone by the filaments of the disc. 
A and B. Sucker and runner formed as attachment to the rock. C. A swollen 
multinucleate tip. D. A branching tip. E. Hapteron structure with five long 
arms. F. A group of cells cut off at the tip of a filament (Grubb) . . . 135 
Outline drawing of a proliferating disc of Porphyra umbilicalis. The actual attach¬ 
ing surface (a) of the central disc is shown giving rise on either side to lateral 
attaching surfaces. From the upper surface of the main disc four young fronds 
have arisen (b) as well as the main frond (Grubb) . . . . . .136 
5. Outline drawing of a young sporeling of Enteromorpha compressa, showing the 
creeping prothallial base (one layer of cells thick) and two linear fronds arising 
from it. 6. Outline drawing of the base of the sporeling seen in Plate I, Fig. 2, 
showing the first six rhizoids enclosed partially in a gelatinous sheath (Grubb) 137 
7. Outline drawing of a longitudinal section of Porphyra umbilicalis growing on 
wood (a), showing the disc attachment with creeping base (b) and thickened 
tissue formed by branching and division of the filaments (c). Five fronds with 
thick gelatinous walls (stippled) are being given off from the disc. 8. Outline 
drawing of a longitudinal section of Porphyra umbilicalis, var. laciniata, on Fucus 
serratus, showing irregular attaching base of Porphyra creeping along the host. 
Fig. 5 of Plate I is taken from the region a, where the cells of the host are 
disorganized (Grubb).138 
Portion of total colony. B. Portion of skeletal systems of colony dissected out. 
C. and D. Side and front view of cylindric cell. E and F. Side and front view of 
cordate cell (Crow)..142 
1, normal female flower ; 2, rudimentary hermaphrodite flower with inferior ovary ; 
3, male flower with vestigial pistil, the latter having a superior ovary and two 
stylar arms ; 4, male flower with androecium only ; 5, vertical section of andro¬ 
gynous inflorescence with rudimentary hermaphrodite flowers on inside lateral 
walls of cupule and male flowers terminally on same ; 6-9, diagrams of normal 
and abnormal female inflorescences showing relation of cupule segments to 
position and number of flowers (shaded) ; 10, vertical section of inflorescence 
whose diagram is represented in 9, taken through plane xy —vascular system as 
seen macroscopically, shaded; 11, diagram of theoretical inflorescence with 
seven possible flowers of dichasium present (Cole) . . . . . .148 
1 and 2, transitional inflorescences; 3, weakly developed male do. (Cole) . . 149 
2. 
