HEMIPTERA. 123 



a great distance, and that they arrived in Belgium by the sea-coast. 

 Whatever be the explanation of the phenomenon, it establishes 

 sufficiently the prodigious multiplication of these little insects. 



There is another trait, and without doubt the most curious in the 

 history of the aphides, to which we have still to call the attention of 

 the reader : we mean the relations which exist between them and the 

 ants. 



No one can have failed to observe ants frequenting those places 

 where plant-lice are gathered together in great numbers. Are ants 

 simply friends of the plant-lice, as thought the ancients ? or have 

 their visits some selfish object ? 



Linnaeus, Bonnet, and Pierre Huber thought that the ants did not 

 pay these visits for nothing, and that they had some object in view. 

 But what could they want of the plant-lice ? It is to Pierre Huber 

 we owe the solution of this mystery. This naturalist has made the 

 most beautiful observations on the relations which exist between 

 plant-lice and ants. They are detailed in a chapter of his admirable 

 work, entitled " Recherches sur les Mceurs des Fourmis Indigenes." 



The plant-lice have, as we have said, at the extremity of their 

 abdomen, two small movable horns. These are in communication 

 with a little gland which produces a sugary liquid. When one care- 

 fully observes plant-lice attached to the stem of a plant, one sees a 

 little syrup droplet oozing out of the extremity of these tubes. 



M. Morren, who has made some interesting observations on the 

 anatomy and generation of the aphis, says that, having shut up 

 females in wide-mouthed glass bottles, he saw the young, a little time 

 after their birth, suck the sweet juice which exudes from the little 

 tubes at the extremity of the mother's abdomen. This secretion 

 seems, then, destined for the nourishment of the young* in the first 

 moments of their existence, before they are able to nourish them- 

 selves on vegetable juices. The saccharine fluid produced by the 

 mother must be, then, a sort of milk intended for the nourishment of 

 her young. This being settled, attend to what follows. In all places 

 where plant-lice are assembled in great numbers it is easy to observe 

 how excessively fond ants are of the sugary liquid destined for 

 suckling the young. But how do the ants manage to get the plant- 

 lice to allow themselves to be, as we may say, milked ? 



" It had been already noticed," says this celebrated observer, 

 " that the ants waited for the moment at which the plant-lice caused 

 this precious manna to come out of their abdomen, which they 

 immediately seized. But I discovered that this was the least of their 

 talents, and that they also knew how to manage to be served with 



