Juty-Aucust, 1g20.] THE ORCHID REVIEW. IIf 
ORCHID HYBRIDISING 4 
(Continued from page 93.) 
HE method of preparing pure cultures of the symbiotic fungi in Orchid 
roots is next described by Mr. Lumsden. Both aériel and ordinary 
roots are utilised. They are first washed thoroughly to remove any 
particles of dirt or other foreign matter, then cut into one-and-a-half inch 
lengths, the external surfaces being sterilised by immersion for one-half to 
three minutes in a seven per cent. solution of calcium hypochlorite. 
Inoculations are made in a small room constructed specially for the 
purpose. A fine water spray is used to cleanse the air of any floating 
material, and the table, hands and arms are carefully sterilised. 
Instruments, such as scalpel, forceps and needles, are flamed after each 
operation. Every possible precaution is taken to isolate the true mycorhizal 
fungus. Small pieces of root, about one-eighth of an inch long, are cut off, 
and transferred to the Petri dishes containing the nutrient agar, and the 
cultures are grown in the dark, under average humidity, at a constant 
temperature of about 25° C. Out of a series of about one hundred cultures, 
only two organisms have occurred with any noticeable regularity, and 
there has been no contamination. 
Mr. Lumsden firmly believes that Orchidaceous plants have become, 
as it were, specialised on various root fungi, and it is remarked that 
experiments with a large number of crosses of the Tribe Vandee, 
Cypripediee, and Epidendree are definitely showing that a separate 
organism is required for each tribe, and perhaps in some cases genus, and in 
very specialised cases, species. : 
Work is still in progress along these lines, and more definite conclusions 
will be presented in an article at a later date, illustrated with photo-micro- 
graphs showing the relation between the Orchid seed and the fungus, which 
it is suggested is perhaps one of mutual parasitism rather than of mutual 
symbiosis. 
(To be continued.) 
CATTLEYA MurIEL.—The three-flowered inflorescence of a very charm- 
ing albino Cattleya has been sent from the collection of Mrs. J. J. Neale, 
of Oxton, Kenton, near Exeter, by Mr. E. Swinden, who remarks that its 
parentage is C. Dusseldorfii Undine x C. Mendelii alba. Iti flowered out 
of a batch of crosses obtained at the Ogilvie sale, and Mr. Swinden wishes 
it'to be named after Miss Muriel Neale, who is a great lover of Orchids. 
The flowers are pure white, of excellent shape, and with a light yellow 
disc"to the lip.3 
