108 MR. Н. М. WARD ON THE STRUCTURE, DEVELOPMENT, 
action of the green-coloured protoplasm*, we must suppose that the latter body becomes 
in part destroyed when the intensity of light and temperature approach a maximum. 
This appears still more probable on examining fig. 6 с, where the cell-contents are seen 
to have undergone yet further (oxidation ?) changes. 
In this case the leaf and thallus had been exposed to a blazing sun in the hot dry 
season for some time, and the oily drops had become reduced in quantity without any 
restitution of green colour; but certain waxy-looking, colourless, vacuolated globules in 
the cells seem to have replaced the partially destroyed cell-contents. Of the exact nature 
of these bodies I can give no information; but it seems almost certain that they were 
formed under the prolonged action of intense metabolism of the coloured proto- 
plasm +. 
MYCOIDEA PARASITICA, Cunningham. 
In the ‘Transactions’ of the Linnean Society of London for January 1879 (2nd series, Bot. 
vol. i. p. 301) appeared a remarkable paper by Mr. D. D. Cunningham, bearing the above 
title, and which was brought to my notice after much of the work detailed in the preceding 
essay had been completed. From a careful and critical examination of Mr. Cunningham's 
able memoir, it seemed probable that the Cryptogam to which he gave the above name, 
and which he found in Caleutta on the leaves of Camellia japonica &c. ** as a destructive 
blight,” may be identical with the Alga found by me in Ceylon. If not, we are at least 
concerned with closely allied species, as I have convinced myself by actual examination 
of Mr. Cunningham's preparations} (unfortunately in a bad state of preservation) now 
in the British Museum. 
The Cryptogam described by Mr. Cunningham was observed also on the leaves of 
Rhododendron, several ferns, crotons, and other plants, and on tea, a fact which, as the 
author points out, possibly “lowers the parasitism of the Alga." The firm nature of the 
epidermal covering in all the leaves affected is also noted. 
Cunningham finds that the parts of the Camellia-leaf affected with the Alga become 
destroyed, the diseoloured and injured tissues sloughing away, and sometimes leaving 
holes in the lamina ; and he further attributes this destruction to the distinct and direct 
parasitism of the Algal thallus, which sends haustoria into the leaf-tissues. "The general 
nature of the latter, and of its erect filaments, radiating cellular structure, &c. had been 
already recognized ; and my observations confirm several important points. Some differ- 
ences in detail, however, led me to continue my work, as well as to reexamine the con- 
tested point; and it may be well to take in sequence those observations and inferences 
with which my own are not in accord. It should be mentioned that Mr. Cunningham 
had also recognized generally the relations of the Alga to the formation of a * Lichen," 
though in his examples it appears probable that a different Fungus is concerned and a 
* Unfortunately I have no exact observations to prove definitely that the green colour is due to chlorophyll; but it 
is an obvious inference from all the facts that it is such a substance, 
T Certain facts, not yet completely investigated, tend to show that this is a common phenomenon, as is also the 
immediate passage of products of assimilation into oily matters. 
+ Through the kindness of Mr. G. Murray. 
