264 THE. ORCHID REVIEW. [SEPTEMBER, 1923. 
was described in 1890. It is most allied to Regnieri, but has considerably 
smaller flowers that are produced at about the same period. The colour is 
dark red, with the lip ruby-red, but some are blush tinted, and others pure 
white. 
TREATMENT OF BACK BULBS OF CATTLEYAS. 
HE usual method of increasing the stock of special varieties consists of 
separating a portion of the plant by dividing the rhizome with a 
sharp knife. The part so cut off can be left in its original position until new 
growth is made, or else removed forthwith and placed in a separate pot. 
Messrs. Flory & Black make a regular practice of maintaining their stock 
of fine Cattleyas by so dividing them. The separated portions are put in 
small pots and surrounded with compost in the usual manner, when they 
are placed in a shady part of the house. Much of the success achieved in 
quickly obtaining vigorous little plants is due to the method of watering 
adopted. The newly potted plants that have roots are kept on the dry side 
for the first few weeks, while those without roots are given more moisture. 
Paradoxical as this may appear, the method has proved beneficial, for it is 
based on sound principles. In order that roots may. form a close contact 
with the particles of the compost, minute hair-like bodies are produced, 
and these seek out the concealed crevices in their search for nutriment. 
When, in repotting, the compost is removed from the roots, most of these 
root-hairs are destroyed, and the plant’s means of obtaining moisture is 
correspondingly decreased. Consequently, in potting these back-bulbs it is 
advisable to keep them on the dry side until the roots re-establish them- 
selves by the formation of new root-hairs, for until this takes place there is 
but little opportunity for any water in the compost to be utilised, and it is 
the presence of stagnant water that is one of the main causes of the roots 
decaying. As soon as the roots recommence activity more water is applied. 
The back portions of plants that are unfortunately not provided with any 
roots are rather more difficult to re-establish. There is, in their case, no 
need to keep the compost on the dry side, and a continual moist state is 
adopted, for tke plant is only able to.take in a much smaller and inadequate 
supply by absorption through the probable process of osmosis. The 
temperature of the house in which these propagated pieces are treated is 
not maintained at any higher point than usually prevails in the Cattleya 
house, consequently the newly made plants start life under normal 
conditions, and as ventilation is freely given their constitution is strong. 
MANCHESTER OrcHID SociETy.—The next meetings of this epaiety will 
be held on September 6th, 2oth, and October 4th. 
