CLASSIFICATION OF DIPTERA. 9 



merdam, who, after years and years of work, brought out his " His- 

 toria Insectorum Generalis." It was first published at Utrecht in 

 1669. This work was afterwards pubHshed in French, Latin, and 

 EngHsh. At first the value of this publication was not known, and 

 no one would publish it in England until 1758, and it was then 

 printed with the edition of the " Biblia Natural." The scheme of 

 arrangement presented in this work is very different to any preceding 

 author. He classed the insects in four groups : 



1st Group or Class : No change of form, but which quit the egg in the same 

 state and appearance they are to retain during life (Spiders, onisci, etc.). 



2nd Class : No wings on leaving the egg ; other members formed ; after 

 passing out of a nymph state wings appear and the insect can breed 

 (Locusts, dragon-flies). 



3rd Class : Animal is in a disguised state before issuing from the egg, and then 

 eats and grows, forming the members of the insect into which it is 

 to be converted under the skin, and which it leaves, and then it is the 

 pupa or chrysalis (Moths, etc.). 



4th Class : The pupa retains two skins, one the larval (Ichneumon). 



In 1688 Blankaart's " Schou Berg der Rupsen, Wormer, Maden, 

 etc.," was published. This Dutch physician in this work gave an 

 account of many larvae, including a dozen fly larvae. The plates in 

 this are wonderfully executed for the age. 



The eighteenth century produced many great entomologists, and 

 at the end we shall see an immense advance in entomological know- 

 ledge. At first came Ray, Lister, and Reaumur. 



Ray's great work was "Historia Insectorum," published in 1810, 

 after his death, by Dr. Derham. This great naturalist divided the 

 insects into two sections : 



(i) Those that undergo transformation in their form. 

 (2) Those that do not pass through any transformation after 

 being produced in the first instance. 

 He formed his orders according to a number of characters, such 

 as the feet, the habits, odour, larvK, etc. He included the Vermes 

 in his classification of insects. He may have considered these in- 

 cluded Vermes as the larval stages of insects. 



Between 1734 and 1742 Reaumur published a five-volume work 

 entitled " Memoires pour servir a I'Histoire des Insectes." This 

 work contained as many as two hundred plates, and was the best 

 work published so far. There were two editions, one in French and 

 another in Dutch. This work of Reaumur's put fresh energy into the 

 entomologists of the Continent. 



Almost at the same time as Reaumur's writings there commenced 

 to appear papers by the great Swedish naturalist, Linnaeus. In 1735 

 he published the first edition of his renowned and valuable work. 



