Objects for the Microscope. 67 



PROBOSCIS OR TONGUE OF BLOW-FLY. 



This is a true proboscis, but not so well seen alone if all 

 its parts and uses are to be considered ; you should have 

 the proboscis of a Gnat and of a Tabanus or House-fly 

 rightly to understand the whole. 



We see the little House-fly busy in our sugar-basin, or 

 the Blow- fly, unwelcome in our larder. We feel the tire- 

 some tickling on a hot summer's day when they gambol 

 over our hands and face ; but we know not how beautiful 

 is that little mischievous tongue. Here it is spread out, 

 the simplest form having a broad fleshy lobe which is 

 striated with spiral fibres, by which it obtains a sucking 

 movement and draws up the juices it feeds on. Little short 

 stiff hairs are set around it, and these are what do us 

 mischief in rasping off the polish of our book-covers, and 

 causing the irritation to our skin. 



PROBOSCIS OF TABANUS. 



This is the more complicated proboscis of the Tabanus, 

 or Horse-fly. Who does not know how it torments our 

 cattle, and the carriage horse in particular, in a dusty drive 

 through the country ? A large brown Fly, with variegated 

 wings, and such magnificent eyes ! She is easily caught ; 

 for when she fixes on the horse and tastes the warm blood, 

 her whole attention is given to the feast. I say she, be- 

 cause the male Tabanus is found harmlessly hovering over 

 flowers, and loves the haunts of the Honey Bee : his mouth 

 has no lancets, whereas the female is supplied with very 

 powerful instruments of assault. 



The head should always be mounted with the proboscis, 

 which greatly increases the interest of the slide ; because, 

 although the eyes lose in preparation their gorgeous colour- 

 ing of green, purple and gold, in zigzag bands across the 

 facets, yet the delicate network remains, and shows the 4,000 

 meshes, which in life each contained an eye. As is the 

 case with many of the Diptera, the eyes of the female are 

 parted by a narrow band. Beneath the eyes, near the 

 mouth, are the antennse, which are supposed to be organs 

 of hearing, as they certainly are of feeling. Six-jointed 



