154 
Notes . 
When the mycelium is well established in the host tissues it proceeds to the 
formation of conidia. Hyphae collect beneath the epidermis and form a subiculum 
on which arises a dense mass of conidiophores, and this leads to the rupture of the 
• 
conidiophores are very variable in form. The simplest 
ones are upright hyphae terminating in a single coni- 
dium, but more usually the conidiophore bears a terminal 
vesicle to which a whorl of pedicellate conidia is at¬ 
tached. The more complex types may show a series 
of such enlargements, each with a whorl of conidia or 
with lateral fertile branches replacing some of the latter. 
The conidia are spherical in form, strongly echinu- 
late, with an average diameter of 35 borne on pedicels 
which vary in length up to 30 /a. 
Not only are conidia produced on the outer surface 
of the fruit, but in Theobroma they are found on the 
inner surface of the ovary wall, in mucilage sacs or even 
in the wider intercellular spaces. 
The conidia found in the internal cavities of the 
fruit are often of larger diameter than the normal type 
and invariably have much thicker walls; they are perhaps 
better regarded as chlamydospores. Their germination 
has not been observed. 
The conidia germinate readily both in water and 
in nutrient solutions. In all cases so far observed they produce a germ tube, which 
under suitable conditions gives rise to a mycelium on which the characteristic conidia 
are developed. The fungus is thus readily grown on artificial media, and pure 
cultures have been established and used in infection experiments. 
Sexual Reproduction. The tissues of diseased cocoa pods bearing the character¬ 
istic conidia show also an abundance of sexual organs of Peronosporineae type. 
These are almost invariably found inside the host cells, singly or in groups; very 
rarely they may occur in the mucilage cavities of the pericarp. They arise from the 
intracellular branches of the mycelium, and may have associated with them groups of 
rounded vesicles. The oogonia are small, averaging 40 x 24/x, rather thick-walled, 
and characterized by the presence of irregular sac-like outgrowths. These latter 
structures vary considerably in size and shape, from short rounded bosses to long 
finger-like processes, often curved and sometimes even faintly forked. The antheridia 
are amphigynous, completely surrounding the stalk of the oogonium in the manner 
hitherto only described for species of Phytophthora by Pethybridge 1 and Dastur. 2 
1 Pethybridge, G. PI.: On the Rotting of Potato Tubers by a New Species of Phytophthora having 
a Method of Sexual Reproduction hitherto undescribed. Sci. Proc. Roy. Dublin Soc., N. S., xiii, 
No - 35 , i 9 I 3 » P- 5 2 9 - 
Lafferty, H. A., and Pethybridge, G. H.: On a Phytophthora parasitic on Apples which has 
both Amphigynous and Paragynous Antheridia; and on Allied Species which .show the same 
Phenomenon. Ibid., xvii, No. 4, 1922, p. 29. 
2 Dastur, J. F.: On Phytophthora parasitica, nov, spec. Mem. Dept. Agr. India, v, No. 4, 
I 9 I 3 , PP* I 77 " 2 3 I - 
overlying epidermis. The 
whorl of 5 conidia, c , and a 
secondary vesicle, v 1 , on which 
conidia are beginning to develop, 
x 750. 
