Index . 
xi 
Figures. 
page 
showing protoplasmic contents and a nucleus. B, ditto of elongated 
parenchymatous elements which function as phloem (Maybrook) . 501 
3. A, diagrammatic median longitudinal section of haustorium in a plane 
of a longitudinal section of the mother root and transverse section of 
host- root. B, detailed drawing of a portion of haustorium repre- 
sented in a. c, diagrammatic obliquely longitudinal section of root 
of Pedicularis attacked by two haustoria and bearing two haustoria 
which are attacking roots of Calluna. d, portion of haustorium h 1 
in detail (Maybrook) 504-5 
4. Detailed drawing of a few cells at the penetrating end of a Pedicularis 
haustorium, showing unique arrangement of haustorial tracheidal 
element (Maybrook) 507 
5. A, detailed drawing of cells of penetrating piliferous layer of haustorium, 
one of which has become lignified. B, ditto of optical section of 
cell of ‘ nucleus ’ which has become lignified. c, transverse section 
of cells of nucleus which have become lignified. D, obliquely trans- 
verse section of element of tracheidal plate showing protoplasmic 
contents and granules (Maybrook) ...... 509 
1. A, portion of a typical filament of the Woodford form of Hormidium 
flaccidum growing on damp soil. B, cell containing two polar 
vacuoles. C, cell containing several small vacuoles in place of one 
of the polar vacuoles, d, e, parts of filaments showing abnormal 
cell-divisions (Piercy) . 514 
2. a, false plate of cells formed by cohering filaments of Hormidium 
after drought, b, cell of a narrower form of Hormidium flaccidum 
infected by a parasite, c, showing escape of the parasitic organisms 
from the Hormidium cell (Piercy) . 516 
3. A, bend in a filament, causing * cuticle ’ at the concave surface to 
become corrugated, b, biconcave septum in optical section, c, 
thickening substance of septum drawn out between two cells. 
D, disintegrating ‘ cuticle ’ stained by methylene blue, e-t, septa 
stained by Ehrlich’s haematoxylin, in optical section. J, K, septa 
from filaments growing in nutritive solutions stained with Ehrlich’s 
haematoxylin. L, septum in which splitting is nearly accomplished. 
M, cell recently detached by splitting of filament, widened at its free 
extremity. N, curved filament which has contracted on becoming 
dry, showing the ‘ cuticle ’ dissociated from longitudinal wall on 
convex surface, and corrugated on the concave surface of bend 
(Piercy) . . .520 
4. A-K, stages in the production of free aplanospores. L, cell showing 
distribution of refractive granules and masses in superficial proto- 
plasm. M, customary distribution of granules, when numerous. 
N, granules arising in the vacuoles (Piercy) . . . . *523 
5. Curves to show effect of desiccation (Piercy) 530 
6. A, cell in which the special substance stained by Sharlach R is dis- 
tributed as fine drops in the surface of the protoplasm. B, accumula- 
tion of the same substance in the vacuoles, c, ditto, the stained 
substance appearing partly in the form of large drops. D, small 
granules produced in a previously clear cell on the withdrawal 
of water from it by means of weak glycerine (Piercy) . . . 535 
