AQUARIUM. 



18 



ARALIA. 



num, are now removed to the genus 

 Linaria. 



Aphis. — The green fly or plant- 

 louse is one of the most troublesome 

 insects to the gardener, particularly 

 on rose trees. These insects lay their 

 first set of eggs (which are small and 

 black) in autumn, near the axils of 

 the buds. These eggs are hatched in 

 February or March, but as only a few 

 insects appear, they generally escape 

 unnoticed, and, after twice casting 

 their skins, arrive at their full growth 

 in April. From this period to the end 

 of summer, brood after brood is pro- 

 duced with almost inconceivable ra- 

 pidity ; and as these aphides are all 

 born alive, they begin to devour the 

 plants on which they appear imme- 

 diately. The tenth generation usually 

 appears about September, and these 

 insects lay eggs for the first brood the 

 following spring. The best way of 

 preventing the attacks of these insects 

 is washing the branches of the rose 

 trees with soft soap and water in 

 January or February ; or, in short, 

 any time before the buds begin to 

 swell. When they have appeared, 

 the best way to destroy them is to lay 

 the infested branches on the hand, 

 and gently to brush off the insects with 

 a soft brush. Some gardeners employ 

 tobacco water, but when this is used 

 the shoots should only remain a few 

 seconds in the tobacco water, and then 

 be washed immediately in clean cold 

 water, or they will become so black- 

 ened and withered, that the remedy 

 will be worse than the insects. Snuff 

 and lime-water are liable to the same 

 objections, as both greatly disfigure the 

 plants. 



Aquarium. — A pond, basin, or cis- 

 tern of water, for the growth of water 

 plants. In a pond in the open garden, 

 the plants may either be grown in 

 pots, plunged to the depth of one or 

 two feet in the water, or they may he 

 planted in the bottom of the pond. 



The former is generally the best mode, 

 because the plants are by that means 

 kept distinct, and th stronger cannot 

 overpower the weaker. At the same 

 time very strong ground plants, such 

 as the white and yellow water-lilies, 

 do not flower freely unless in the free 

 soil, or in very large tubs. There 

 are few greenhouse aquatics, but a 

 number of stove plants, which re- 

 quire to be grown in water; such as 

 the Indian Lotus, or Nelumbium, 

 &c, and these are necessarily grown in 

 pots of moderate size. The most suit- 

 able soil is a rich loam. The papyrus, 

 though properly speaking it is a marsh 

 plant, is generally grown in an aqua- 

 rium. See Marsh Plants. 



Aquilegia. — Ranunculaceee. — 

 The Columbine. Perennial herba- 

 ceous plants, growing from one to two 

 feet high, of which several species are 

 very ornamental ; more especially the 

 common columbine, A. vulgaris, and 

 its varieties, A. alpina, A. canaden- 

 sis, and A. glandulbsa. They grow 

 in any common soil that is dry ; 

 and the species are increased by seeds 

 which will keep a long time, and the 

 varieties by division of the root. 



Arabis. — Cruciferce. — Wall-cress. 

 Herbaceous plants, chiefly annuals and 

 biennials, natives of Europe, many of 

 which are remarkable for their early 

 flowering. A. alpina has white and 

 yellowflowers, which appear in March, 

 and A. dlbida flowers the greater part 

 of the year, commencing in mild win- 

 ters in January, and producing its large 

 tufts of white blossoms till October. 

 Some of the species and varieties, such 

 as A. verna, A. alpina nana, and 

 A. bellidifblia, do not grow above 

 three inches high, and are admirable 

 plants for rockwork, or gardens of 

 pots. 



Aralia. — AraliacecB. — Hardy suf- 

 fruticose plants, and stove shrubs, with 

 umbels of small white flowers. The 

 commonest species is A. spinosa, 



