MONOGRAPHY OF THE GENUS CAMELLIA. 29 



sponge, if it is not continually cleansed, absorbs the dust of the leaves, and 

 communicates it to those to which it is successively applied, it also leaves a 

 little humidity on them, which immediately collects the dust again. 



The best method is, to use a small piece of fine and dry linen, or cotton 

 cloth with which the leaves are to be lightly and carefully rubbed 3 they im- 

 mediately acquire all their natural lustre and present a renewed appearance 

 of health and vigor. 



While the Camellia is in the green-house, and even when in the open 

 air, a kind of moss, which is often produced by the quality of the water used 

 in irrigation, is formed, which covers the superior surface of the earth in 

 the pots. It is, therefore, necessary, when the plants are removed from, or 

 restored to the green-house, that this moss should be carefully taken off, and 

 with it as much of the earth as possible, which is to be replaced, with such, 

 as has been prepared, for the purpose, in the manner, that has been de- 

 scribed, and which has a vivifying effect on the plants. 



Section 7. — The insects which are injurious to the Camellia. 



The Camellia is attacked, both, when in the green-house, and exposed to 

 the open air, by several small insects, which are the aphides^ (plant lice,) 

 formica y (ants,) kermes^ (a small beetle of the coccus genus,) cochineal ^ 

 (also a beetle of the coccus genus,) &c. 



It is not an easy task to destroy these various kinds of insects, and the 

 process we shall describe requires great care and attention. 



The Aphides are developed early in the spring j they attach themselves 

 to the most tender shoots, and cover them so completely, that the bark seems 

 to have changed its color 5 and are constantly pumping the abundant sap, 

 with which the young branches are filled, and they consequently languish. 

 The leaves fade and soon perish, if the insects are not either removed by the 

 cultivator, rains or certain winds which are fatal to them. They are readily 

 destroyed by burning tobacco in the green-house, washing the infected 

 branches with soap suds, or, what is still better, crushing them with the 

 fingers. 



Although it is said, that the formicse live at the expense of the aphides, 

 we believe there are some of the species, which are nourished by the tender 

 twigs of the Camellia; besides, their numerous progeny is very inconveni- 



