SOME INSECT ADAPTATIONS. 
87 
even able to feather as they row along, yet here, as 
elsewhere, the plan of structure is the same as that 
Fig. 80.—Fore Legs of a Water-bug. B , open; A , closed; C, enlarged 
• to show sheath. 
seen in the cockroach and grasshopper. Some butter¬ 
flies of strong flight use their legs so little that their 
front legs are mere threads, yet they retain the marks 
Fig. 81.—Legs of Dyticus. A , hind legs for swimming; B , fore leg 
with suckers. 
of the same plan we have found in the other insects 
examined. 
What is true of the legs is also true of other impor- 
