78 THE GRCHID REVIEW. [MasRcH, 1922. 
ORCHID MYCORRHIZA. 
‘JT is hardly necessary to remind anyone of the numerous hybrids that 
have been produced by Messrs. Charlesworth & Co. Almost all the 
popular genera have at one time or another been taken in hand and _inter- 
crossed as far as natural limitations admit. But although a certain degree: 
-of success was obtained with Odontoglossums and the allied genera, the 
results did not satisfy the ambitions of the late Mr. Charlesworth, so he set 
out to study the fungus question, and to evolve new methods of culture. 
The present editor of this journal well remembers the commencement of 
this work, and the difficulties that then presented themselves induced him 
to recommend Mr. Charlesworth to seek the assistance of Mr. ds 
Ramsbottom, of the British Museum. A personal introduction took place 
at the Royal Horticultural Society’s Holland House Show, and resulted in 
Mr. Ramsbottom paying a visit to Haywards Heath, in the year 1913. Of 
the many important and beautiful cool house orchids that have since been 
‘produced by Messrs. Charlesworth, five are the subjects of coloured 
plates in the 1922 edition of their catalogue, the forepart of which is devoted 
to an article on the theoretical questions concerning the relation of Fungi 
and Orchids by Capt. J. Ramsbottom, O.B.E., M.A., of the British 
Museum (Natural History), who collaborated with Mr. Charlesworth in his 
scientific researches. 
In the introduction it is remarked that one of the most interesting 
phenomena in biology is that generally know as symbiosis—the living 
together of two organisms in close association. It is usually considered 
that this intimate relationship is of benefit to both components. Cells 
containing fungi were first figured in an Orchid, Goodyera procera, by Link 
in 1840. Reissek, in 1847, found that in Orchis Morio the fungus was 
present in almost all the cortical cells, whereas in the tropical species the 
fungal masses were arranged singly at the periphery. He also attempted 
‘to extract the fungus from the roots. The fungus usually enters the root 
through the root-hairs, and infection does not generally occur once for all, 
but the hyphz from the soil infect the roots in several places. - Not all the 
roots of an Orchid are generally infected. Aerial roots particularly are free 
from fungus. Large numbers of native and exotic species have been studied 
by Wahrlich, who examined over 500 of the latter cultivated in Moscow. 
GERMINATION OF SEEDs.—It was not until 1804 that any Orchid 
and probably obtained his best results by sowing the seed on the compost 
‘Containing the parent plant. Various methods have since been practised, 
but in general they all consist of sowing the seed on fungus-infected 
