SWAMMERDAM 187 



mouth-opening, which forms no part of the tongue. 

 The proboscis of the bee leads Swammerdam to say a 

 word about that of a moth, which he shows to be 

 double, the halves being co-articulated by innumerable 

 fine hooks. He briefly describes the short proboscis of 

 a wasp, but gives no hint that it is made up of parts 

 answerable to those of the bee, except that he figures 

 the two sets of organs side by side. 



When he comes to the eyes of the bee he remarks 

 that they are larger in the drone than in the queen or 

 the worker, and that besides compound eyes there are 

 three peculiar eyes (now called "simple eyes") on the 

 top of the head. That the compound eyes are true 

 organs of vision had already been demonstrated by 

 Hooke, who had blinded insects by cutting out or 

 injuring their eyes. Swammerdam resorted to the less 

 cruel expedient of smearing the bee's eyes with black 

 paint, and found that bees so treated could not find 

 their way about. By careful figures and descriptions he 

 gives as good a representation of the eye of a bee as 

 could be attained in the days when there were no trans- 

 parent sections, when the development of the parts* had 

 not been studied, and when the best optical knowledge 

 was but elementary. In spite of all defects, Swammer- 

 dam's account of the compound eye is much the best 

 which was ofi'ered to physiologists then or for many 

 years to come. He remarks that certain ingenious but 

 hasty philosophers ("sommige subtiele ende gaauwe 

 geesten"), among them the illustrious Hooke, had 

 supposed the compound eye to be a collection of 

 numerous simple eyes, each fashioned like the eye of 

 man. Swammerdam saw that this comparison gives 

 no true idea of the insect-eye. To the inner surface of 

 each corneal facet is applied a long, slender cone, which, 



