I I 2 PLANT LIFE. 



300 days produce by its own multiplication 210^^ 

 greenflies according to Buckton's computation. Accord- 

 ing to Huxley the loth brood of an Aphis would 

 contain more animal matter than the population of 

 China. These aphides are easily observed in the 

 Sycamore. In dry seasons they multiply so rapidly 

 upon it that the sugary secretion which they give off 

 coats the leaves with a shiny varnish, and may even 

 drip to the ground. This is the " Honey Dew," the 

 " Sweat of Heaven " or " Saliva of the Stars " of 

 Pliny, and others. Ants are fond of sucking their 

 honey, and one {Lasius flavus) collects the eggs of 

 these aphides and stores them, carrying food to them 

 when young. 



To kill them off Miss Ormerod recommends a Paraffin 

 Naphthalene emulsion; a saturated solution of naphtha- 

 lene in paraffin oil, combined with boiling soft soap. 

 This should be used as a solution, i-ij parts in 100 

 parts of water. 



This chapter will have shown the number and impor- 

 tance of the defensive methods employed by plants ; 

 and it will also have shown how many invaluable 

 products are obtained by man from them. Thus to give 

 only two instances, the silk industry, worth annually 

 ;^i 8,000,000, and tea plantations (828,000 acres in 

 India and Ceylon) as well as imports of tea paying 

 yearly to the Exchequer about ;{^4,000,000 sterling, are 

 sufficient to show the importance of plant defences to 

 man. But the fact that the life histories of man, 

 animals, insects, and plants are inextricably entangled 

 with one another, is of the greatest importance to a 

 right conception of Nature, and this is very seldom 

 brought forward in botanical teaching. Such a case as 

 the fungus Ophionectria coccinea, which is parasitic upon 



