BINUCLEATA 



51 



animation of mosquitoes, as these, and especially the genera Anophe- 

 lina and Culicidce, have a great practical importance. 1 



In the first place, the females, which alone have an experimental 

 interest, should be carefully distinguished from the males, and the 

 different species should be distinguished from one another. The most 

 minute attention must be paid to the appearance of the palpi and 

 antennae. In the male, the antennae are covered with long bushy 

 hairs, in the female with short bristles. The palpi of the female 

 Culex are much shorter than the proboscis, while in the female 

 Anopheles they are the same length as the proboscis, and thus a little 

 longer than the antennae (figs. 9 and 10). Various methods of 



a b 



FIG. 9. Head of Culex. a, Male ; b, female. (After Giles, from Braun.) 



catching the flies have been recommended, but the simplest apparatus 

 is perhaps the following : A simple glass tube, about 15 cm. in length 

 and 2 cm. in diameter, is fitted with a cork in which a hole has been 

 bored. Into this hole a small funnel, the external diameter of which 

 is about 6 cm., while the lumen of the tube should measure about 

 5 mm., is introduced in such a way that the small end, which should 

 be cut off diagonally, projects some 2 to 3 cm. into the lumen of the 

 glass tube. The apparatus is inverted over the insect when at rest 

 upon a wall (or other plane surface), and a flat disc of suitable size is 

 inserted between the mouth of the funnel and the wall. This disc 

 should be of metal and should be attached to the cork by means of a 

 fine chain. On being disturbed, the insect flies up and soon passes 

 from the funnel into the glass tube. As, like the eel in the eel-pot, 



1 Directions for the examination of other blood-sucking invertebrates (leeches, 

 ticks, insects) are given in the final chapter of this volume. 



