MaRrcu, 191 4.] THE ORCHID REVIEW. 79 
employed. The plants will require watering more frequently than hitherto, 
and a light spraying overhead may be practised whenever the weather is 
bright. Keep them clean by spraying or dipping in a weak solution of 
XL-AlII liquid insecticide directly any thrip is detected. The coolest end 
of the Odontoglossum house is the best position for Disas, where a top 
ventilator can be always more or less open. When the division is vaporised 
the Disas should be removed until the fumes have escaped, as the tips of 
the leaves are generally injured. 
PHAIOCALANTHES are semi-deciduous subjects, and unless given careful 
treatment they are liable to be attacked with the spot disease, and rot off at 
the base of the bulb. Proper ventilation, and intelligent handling of 
the water pot, will usually prevent such a calamity. After the scapes are 
removed a partial rest is needed in a somewhat dry atmosphere, with only 
sufficient water to maintain the bulbs in a rigid condition. When they 
start into growth repot them in a similar mixture to Phaius, and grow on in 
the same house. The appearance of red-spider and scale insects must be 
watched for, and, when seen, the foliage ought to be sponged over, 
especially on the undersides. 
ONCIDIUMS constitute a varied group of Orchids which for the most 
part can be accommodated in the intermediate division. A few notable 
exceptions, however, embrace O. macranthum, O. superbiens, O. 
monachicum, and others of this section, which will thrive in the Cool 
house. Some of them will now be pushing up their flower scapes, and 
should in consequence be kept well supplied: with water, while any repotting 
must stand over till a later date. Those that are not flowering may be 
given fresh rooting material, which consists of good peat, osmunda fibre, and 
sphagnum moss in equal parts. The compost must not be pressed too tight, 
and for large examples it can be used in a more lumpy condition, so that 
the roots may enter without any hindrance, and water can pass through 
quickly. Where the receptacles are large enough for further development, 
the plants need not be disturbed, unless the soil has become exhausted, 
when it must be picked out and replaced with new compost, avoiding any 
injury to the roots. Most of these species have large fleshy roots, and if 
the lead or growing point happens to be a distance from the surface, it will 
be advisable to fill up the intervening space with pieces of fibre and 
sphagnum moss, or the roots should be trained down to the compost: to 
prevent them being eaten by slugs, or broken when moving the plants. 
Any other Oncidiums that have started into growth, and are about to 
root from the base of the new shoot, may be repotted. For smaller growing 
kinds it is necessary to cut up the fibres rather finer than is required by the 
more robust species. Among those now showing flower are O. concolor, 
O. leucochilum, and others, and these must be afforded liberal waterings 
