. British bee journal & bee-keepers adviser. Bees. 440 THE BRITISH BEE JOURNAL. [October G, 1887. The proboscis is an elongation of the labium (or lower lip), which is modified into a three-jointed sheath, inside which are three sharp-pointed lancets, which have a backward and a forward motion. This suctorial organ is folded on the breast: by its means the insect pierces the skin, and extracts the juices of the leaves or the roots of plants which form its nourishment. The length of tho proboscis varies in different kinds, some being very short, and others quite as long as the insect itself
. British bee journal & bee-keepers adviser. Bees. 440 THE BRITISH BEE JOURNAL. [October G, 1887. The proboscis is an elongation of the labium (or lower lip), which is modified into a three-jointed sheath, inside which are three sharp-pointed lancets, which have a backward and a forward motion. This suctorial organ is folded on the breast: by its means the insect pierces the skin, and extracts the juices of the leaves or the roots of plants which form its nourishment. The length of tho proboscis varies in different kinds, some being very short, and others quite as long as the insect itself: it is also found disproportionately long in the young of some of the aphides. By means of this organ the juices are drawn into the mouth by a kind of pumping movement, similar to that noticed in the proboscis of the bee. The function of the nectaries or cornicles is to give off, as the result of the suction of the pro- boscis, the drops which gradually accumulate at the ends of the tubes. Sometimes, as we have mentioned, these drops fall on the grass saturating with the treacle-like substance the ground, at other times on the leaves, and so choking the stomata, or leaf-pores, and thereby preventing the natural respiration performed by these pores. The nectaries vary much in form and size. In some they attain half the size of the aphis ; in others they are very small; while in others they are altogether wanting. There is considerable difference in opinion as to the part these nectaries play in the economy of the insect. The opinion that of late has prevailed is that they have some connexion with the respira- tory organs. C. Morren considers them to be nothing more than prolonged stomata, the aper- tures leading to the tracheal or respiratory system ; and he states ' that a considerable lacing of tracheae may be seen to start from the points at which the oornicles enter the integument.' Also, he asserts, ' that the air replaces the liquid which is ejaculated from these tub
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