126 IN THE GUIANA FOREST. 



possibly they would be to the naturalist ; but our 

 eyes are fitted for long distances, and there is no 

 doubt they are well suited to our circumstances. 

 We can fancy mosquitoes with long sight, but we 

 cannot conceive of man living with them under 

 such a condition. Were the billions of these blood- 

 suckers to see him enter their great preserve, the 

 swamp, and all come round on him at once, care- 

 fully made nettings would have to be always worn. 

 But, fortunately, they have their limitations, and 

 when they see us at first it is probably as in- 

 distinct shadows, and the preliminary investigation 

 of our faces may be the result of some odour or, 

 when we move, of the vibrations set up for a few 

 yards in every direction. 



Besides the limitation from microscopic eyes 

 which, however, see all the better at the right 

 focal distance, there is the drawback to them of 

 the want of ears. As far as can be gathered at 

 present insects do not hear ; at the same time, how- 

 ever, it may be safely stated that sounds are fairly 

 well distinguished by feeling. We cannot suppose 

 that the vibrations which may indicate the 

 approach of enemies are unfelt. On the con- 

 trary, it may safely be presumed that the antennae 

 distinguish movements of such a delicate nature 

 that they are quite inaudible to us. 



