ORGANS FOR BREATHING IN WATER-GRUBS. 157 



like the grub of the gnat, we know not, but they 

 perfectly repel water ; and at the point where the 

 insect hangs suspended, a small dimple may be 

 observed on the surface. When it wishes to dive to 

 the bottom, it has the power of bringing the ends of 

 the hairs together, without diminishing the capacity of 

 the funnel below ; and a globule of air, for the pur- 

 pose of breathing under water, is thus inclosed and 

 carried down, appearing, as Swammerdam says, like 

 a briUiant pearl or polished silver. " As for my 

 part," he adds, " I dare boldly affirm, that the incom- 

 prehensible greatness of the Deity manifests itself in 

 these mysterious operations in a particular manner, 

 g.nd affords us an opportunity of examining, as it 

 were, with our senses, the divine nature *." 



Bsoj-like struct ire in the tail of a water-grub of a tvvo-wingcd fly 

 (^Stratiumys Ckamccleon). 



* Swammerdam, part ii. 51. 



