HONEY-DEW 1G9 



wlion tlio tertiary deposits of (Kninpon aiul Radoboj wcro 

 laid down, Dr. Hcer of Zuricli has shown that at least 

 eighty-three distinct species of ants ah'cady existed ; and 

 the number that have left no trace behind is most ])robahly 

 far greater. Home of the beetles and woodlice which ants 

 domesticate in tlieir nests have been kept underground so 

 long that tliey have become quite blind — that is to say, 

 have ceased altogether to produce eyes, which would be of 

 no use to them in their subterraiman galleries ; and one 

 such blind beetle, known as Claviger, has even lost the 

 power of feeding itself, and has to bo led by its masters 

 from their own mandibles. Dr. Taschenlx^rg enumerates 

 800 species of true ants'-nest insects, mostly beetles, in 

 Germany alone; and ]\I. Andre gives a list of OHl kinds, 

 habitually found in association with ants in one country or 

 another. Compared with tluise singular results of formi- 

 can selection, the mere production or further dev(;lopment 

 of the honey-tubes apjiears to bo a very small nuitter. 



But what good do the aphides themselves derive from the 

 power of secreting honc^-dew ? For we know now that 

 no animal or plant is ever provided with any organ or 

 part merely for the benefit of another creat)n'e : the 

 advantage must at least be mutual. Well, in the first 

 place, it is likely that, in any case, the amount of sugary 

 matter in the food of the a|)hides is (juite in excess of 

 their needs ; they assimilate the nitrogenous material of 

 the sap, and secrete its saccharine nuiterial as honi^y-dcw. 

 That, however, would luirdly account for the devel()])nu'nt 

 of special secretory ducts, like the honey-tubes, in which 

 you can actually see the little drops of honey rolling, under 

 the microscope. But the ants are usehil allies to tho 

 aphides, in guarding them from another very dangc^'ous 

 type of insect. They are Bul)ject to tlie attacks of an 

 ichneumon lly, which lays its eggs in them, meaning ita 



