ROESEL VON ROSENHOF 299 



cold season they rested in a temporary cocoon, which 

 they made in the wood. When food ran short, the 

 stronger ones ate the weaker, leaving nothing behind, 

 for even the hard integument of the head was crushed 

 by the powerful jaws and swallowed. At pupation a 

 cocoon was made of sawdust (or rather of gnawed wood) 

 held together and lined by silk. The long larval stage 

 was followed by a short pupal stage, lasting three weeks 

 or less. When the time of emergence arrived, the pupa 

 burst through its cocoon, and lay with the fore part of 

 its body exposed until the moth was ready to escape. 

 Moths of both sexes were obtained ; the males were dis- 

 tinguished by their pectinate antennae. Eoesel tells us 

 that the fertile female lays her eggs in the cracks of oak 

 bark, so that the issuing larvae can easily procure a 

 supply of the sap, which is their first food. 



The Crayifish 



Many readers of Huxley's Crayfish will remember 

 that he extracts some amusing remarks from Roesel, 

 w^hose account of this "insect" is almost worthy of 

 Swammerdam. Roesel figures the external form, the 

 chief viscera, the scaphognathite (which he describes as 

 an implement with which the crayfish brushes its teeth), 

 and the leech-Bke Branchiobdella, which attaches itself 

 to the gills. But why does he give the crayfish the 

 colour of a boiled specimen ? 



Dispersal of Fruits and Seeds 



Having finished his account of the water- beetles, 

 Roesel should have taken up the dragon-fiies, which 

 come next in his plan of description, but here we find 

 interpolated, much to our surprise, an account of winged 

 and plumed fruits and seeds. Roesel apologises for his 



