208 THE MINUTE ANATOMISTS 



emergence. He fed his larvae on fresh-killed flies, and 

 after twelve or thirteen days observed them change 

 to pupae. He utterly repudiates the doctrine of Kircher 

 that fleas are generated out of dust and filth. If 

 Kircher is to be trusted, he says, we must suppose that 

 fleas are generated in Italy after a very different fashion 

 from that which prevails in Holland. 



Hooke, Roesel and De Geer are among the other 

 naturalists who investigated the flea. 



Arils'^ 



Ants are sometimes seen to carry about large, white, 

 rounded bodies, which are popularly known as "ant- 

 eggs." Leeuwenhoek copies and criticises Griendel's 

 figure of one of these, which shows an eight-legged ant 

 walking about in a relatively large chamber. He shows 

 that the supposed egg is really a pupa, and that the real 

 eggs are much smaller. He rejects the belief that ants 

 store up food against the winter, which is nevertheless 

 true of the ants of warmer countries. 



The Nature of Cochineal 



Cochineal had been regularly grown by the Indians 

 of Mexico before the arrival of the Spaniards, and since 

 careful transfer of the insects from old Opuntia-plants to 

 new ones is an essential part of the process of cultivation, 

 they must have known, one would think, what was the 

 real nature of the grains exported to Europe. It was 

 however long debated by the learned men of England, 

 France and Holland whether cochineal-grains are insects 

 or fruits. One anonymous writer of 1668 gave it as his 

 opinion that the dye-stuff consisted, not of fruits of the 



1 Cont. Epist. (1687). Vol. I, pp. 75-90. 



