1895 THE MICROSCOPE. 131 



of the minuteness and delicacy of the parts). These, we 

 are told, consist of two mandibles, which are narrow 

 blades with a stronger back like a scythe; their tip is 

 brought to a most acute point and the edge in immediate 

 proximity to this is cut into about nine teeth pointing 

 backward; the rest is smooth (fig. 2, n). Next come two 

 maxillae or lower jaws, having filaments as long as the 

 former but still more delicate, consisting of simple cut- 

 ting lancets with a back and keen blade (fig. 7, m). Be- 

 sides these there is the tongue, consisting of a central 

 rod which is distinctly tubular with a thin blade on each 

 side, fine edged and drawn to an acute point (fig. 7, t). 

 There is also the labrum or ujiper lip. This is an im- 

 perfect tube svhich serves as a sheath for the tongue 

 (fig. 7, o). The labium is about one-sixth of an inch in 

 length. The insect inserts the lancets into the flesh to 

 their full length, the labium being folded back, then 

 through a tube in the tongue it is supposed that a poi- 

 sonous fluid is injected into the wound to dilute the blood 

 and that the blood is then sucked up through this same 

 tube. 



The life history of this insect is interesting. When 

 the female is about to deposit her eggs she selects some 

 floating stick or straw and places her front legs upon it; 

 she then allows the middle pair to rest upon the surface 

 of the water and crosses the hind pair over them to look 

 like the letter X. She then deposits a spindle-shaped 

 egg in an upright position in the angle of the X, and an- 

 other by the side of it, gluing them together with a 

 cement which is not affected by water. This is con- 

 tinued until a mass much the shape of our life boat is 

 formed. In a few days the larvae hatch and escape 

 from the lower end into the water. The larvae (fig. 8) 

 are the well-known *'wigglers," having a long segmented 

 abdomen, the next to the last joint of which bears a 

 breathing tube. The insect, when at rest, hangs head 



