92 THE GREEN-HOUSE. MYRTLES.—MIMULUS. 
extensively than these. The principal parents of the numerous and 
spiendid plants that we are continually seeing produced, are C. 
corymbosa, and C. arachnoidea, the one a yellow, and the other a 
purple flower; but there are many other species that have been 
crossed and re-crossed with these, so as to form a very great variety. 
C. bicolor, with pale yellow-and-white flowers, and C. crenatiflora, 
with spotted flowers, have also been the parents of some very fine 
hybrids and varieties. All the calceolarias require rather a rich soil; 
and the usual compost is two parts of thoroughly rotten dung, one 
part of leaf mould, or old turf, and one part of white sand. The in- 
gredients of this compost should be well mixed together, and broken 
fine, but not sifted. They also require plenty of water, and abun- 
dance of light and air; and they will all flower best when allowed 
plenty of room for their roots. They are, however, very subject to 
be attacked by a kind of aphis: and when kept in pots, they should 
be frequently syringed. The best Calceolarias, near London, are 
those of Mr. Catleugh at Chelsea. 
Myrtles should be grown in a soil composed of peat and loam, in 
which the former predominates; they should be regularly watered, 
and frequently syringed. Some persons nip off the tips of the young 
shoots, to make the plants grow bushy; and though it has this effect, 
it is a bad practice with the flowering kinds, as it prevents them from 
producing flowers. A better plan is to make cuttings, and first to 
plant them in very small pots, gradually changing them into larger 
ones, till the plants have acquired a bushy habit of growth. 
Mimulus.—Some of the plants belonging to this genus are very 
handsome, particularly the hybrids raised by the nurserymen from M. 
ceardinalis, M. roseus, M. luteus, and M. gattatus. These species are all 
herbaceous, and all natives of South America, Mexico, and Califor- 
nia. They are all nearly hardy, and though generally grown in a 
green-house, they will stand quite weil in the ojen air, dying down 
to the ground in winter, but sending up fresh and very vigorous 
shoots in spring. When these plants are grown in the open ground 
it should be in a shady moist situation; and when they are kept in 
pots, they should always stand in saucers half full of water. ‘'Vhis 
water should, however, be changed every day, and when given to 
the plants it should always be as nearly as possible of the same tem- 
perature as themselves. The little musk plant, Mimulus moschata, 
requires the same treatment as its more showy brethren. As all the 
