HARDWICKE'S SCIENCE-GOSSIP. 



153 



a fourth part at first-sight apparently quite devoid of 

 any marking. By careful manipulation with a couple 

 of needles this may be withdrawn, and will be found 

 to consist of two distinct parts, an outer one, or 

 sheath, through which the enclosed needle-like organ 

 freely moves. When the proboscis is in its natural 

 condition, these parts are seen to enter, and are 

 capable of being moved within the cylinder, which 

 •extends for a short distance towards the end of the 

 proboscis. A reference to figure 99 will 



ijive 



and necessary to some extent if we desire to compre- 

 hend the action of the mouth. 



The free ends of these organs are very thin and 

 delicate, and quite inadequate as a means of inflicting 

 a puncture. Their use undoubtedly is to convey the 

 liquid aliment to the oesophagus by constantly sliding 

 the parts within each other, on the same principle as 

 that employed in some instances for lubricating 

 machinery by means of the needle lubricator, which 

 may be familiar to many. 



Fig. 99 —Sucto- 

 rial apparatus of 

 S. calcitrans 

 enlarged, a, 

 sheath(Iabrum); 

 b, needle (lin- 

 gua) ; c, aper- 

 tures, use un- 

 known. 



Fig. 100. — Diagram of Teeth of Stonwxys calcitrans X 330 diatns. , 



some idea of the two parts referred to, the main 

 portion of the proboscis being omitted. 



a is the sheath (Labrum) carrying the needle, b 

 (Lingua) in its concavity, while the convex side 

 being outward completes the cylindrical outline of 

 the proboscis. The aperture at the extremity of the 

 sheath agrees in size, and comes into close proximity 

 to the mouth, or rather that part of it ia which the 

 organs of dentition are situated, and to which these 

 notes are chiefly intended to refer ; but the whole organ 

 is so full of interest I have been led to make these 

 .remarks as bearing in some measure upon the subject, 



The enlarged portion of the proboscis is liberally 

 provided with muscles, and from these tendons 

 extend down to the mouth ; they are very numerous, 

 sufficiently so to supply individual movement to the 

 teeth and other organs therein contained. 



In order to display these organs a different mode 

 of procedure is necessary to that employed in 

 Muscidre. The end of the proboscis must be cut off, 

 and the point of a very fine knife inserted in the 

 opening and laid open, similar to what is done to 

 display the gizzard of a beetle. The operation is 

 well calculated to test the patience of the operator, 



