OPERATIONS FOR FEBRUARY. 
23 
Hibbertia volubilis, they are quite free from the offensive smell of that species. The drawing was 
made in the garden of the Horticultural Society in May last. It there proves to be a greenhouse 
shrub, requiring the same treatment as many other New Holland plants. It grows freely, if 
potted in a compost consisting of peat, loam, and sand in equal proportions. The pot should be 
well drained, and a few pieces of potsherds mixed through the soil. Plenty of air and water must 
be given in summer, and shade in sunny days. In winter the plant should be placed in some airy 
place free from frost, and be watered in fine weather. It may be propagated by cuttings in the 
usual way." As the name indicates, the great peculiarity of the species is its having the leaves 
clasp the stem at the base. BoL Reg. 64. 
Mammilla'ria tetraca'ntha. " The plant figured has long been cultivated in the Cactus-house 
of the Royal Botanic Gardens, Kew, under the above appellation ; and it appears sufliciently to 
accord with that of the same name published by Pfeiff"er, the only author," continues Sir W. J. 
Hooker, " so far as I can find, who has noticed it. His description, indeed, seems drawn up fi-ora 
a young specimen four inches high, and three inches and a half in diameter, with the maraillee and 
aculese small in proportion ; and the flowers were, probably, unknown to that author, since he does 
not mention them. It is a native of Mexico, but by whom introduced to Europe, I do not learn. 
It flowers in July," The flowers are produced abundantly round the summit of the plant, and 
are of a bright full rose-colour, paler in the disk. They are rather small. Bot. Mag. 4060. 
Onci'dium bi'color. " This charming species of Oncidium, one of the rarest of its genus, was 
obtained by Messrs. Loddiges from the Spanish Main. It flowered with them in September, 1842. 
Ameng other peculiarities of the species, may be mentioned its very thin pseudo-bulbs, and three- 
lobed crest of the labellum, the front lobe of which projects forward, while the laterals are at 
right angles to it, and slightly toothed. It has, moreover, a very large lip, which, though deep 
clear yellow on the upper side, is almost white underneath, as also happens in some of the Chive- 
leaved species. Its nearest affinity is with 0. bifolium." It seems quite as beautiful as that fine 
species ; and is, doubtless, equally adapted for growing in a pot, or on a block of wood. Whichever 
way it is treated, the plants should be suspended from the roof of the house. Bot. Reg. 66. 
OPERATIONS FOR FEBRUARY. 
With the exception of two or three days' frost, we have yet had nothing that can be called 
severe weather, and hence, though fuel will have been economized, and also a considerable amount 
of the labour usually bestowed on covering up houses and frames, the plants themselves will 
probably suffer from this unusual mildness. At any rate, it seems likely to be a trying season 
for the cultivator, and to put all his skill to the test ; for while common expedients and ordinary 
watchfulness will preserve plants from being damaged by cold, it is an extremely difficult matter 
to prevent their being injured by the long occurrence of comparatively warm weather in winter. 
So much is said about the precocity of vegetation in the open air, that it is quite impossible 
for exotics, within doors, to have escaped a similar, or even greater stimulation. AH the aims of 
the culturist should therefore be directed to repressing this undue excitement. And this on two 
accounts. First, the days are not — and will not be for some time — long enough, nor the sun bright 
enough, to perfect the young developments that may be made. And, secondly, it is more than 
likely that, before the next two months have passed away, we shall have at least some of winter's 
common attendants, and which, if they occur while plants are in a growing or excited condition, 
will be felt all the more seriously and prejudicially for such a circumstance. 
The obvious modes of checking any kind of growth at this season are, to keep the houses and 
frames as constantly open as the dryness and warmth of the atmosphere will permit. If the 
thermometer is maintained above 45°, or about 48° in stoves, and above or about 40° in green- 
houses, cold pits, and frames, this will be quite high enough ; and when it gets many degrees 
above that, save on those days during which the sun is shining brightly and a large quantity of 
air is supplied, the plants will only be deriving injury. Very damp days are, of course, to be 
excepted. 
Another method of keeping down excitation is to be very sparing in the administration of 
