Plate IV. — Reproduced fbom Malpighi's " De Gaixis." 



Fig. 1. — Gall produced by Aylax glechomae Linne, on ground ivy. Fig. 2. — Section 

 showing the larval chamher and the enclosed larva. 



Fig. 3. — Aphid gall on the leaf of poplar. 



Fig. 4. — Mite gall; the producer was unknown to Malpighi. 



Fig. 5. — Cynipid producer; 6. — ^Abdomen of producer, with ovipositor retracted; 

 7. — The same with ovipositor protruded; 8. — Ovipositor. 



Fig. 9. — Section of a willow gall, produced by a midge. 



90 



