LIST OF ILLUSTRATIONS, 



PAOB 



Human Hair 2 



Hog's Bristle 5 



Fibre of Sheep's Wool 7 



Hair of Cat 8 



Hairs of Mole , . . . 9 



Hair of Sable 9 



Hair of Mouse 10 



Tip of Small Hair of Mouse 11 



Hair of Bat 11 



Hair of Indian Bat 12 



Tip of Hair of Dermestes 14 



Barb of Clothing Feather of Fowl 15 



Barb from Goose-quill 16 



Scales of Perch 17 



Scales of Gold-fish 19 



Scale of Flounder . 21 



Scales of Pike 23 



Spicula of Gold-fish's Scale ....... 24 



Blood Disks 28 



Circulation in Frog's Foot 32 



Perophora 33 



Cuttle-shell 41 



Section of Nacre from Pearl Oyster ..... 43 



Tongue of Trochus 48 



Structure of Eye in Snail 64 



Leafy Sea-mat 62 



Doubling and Hooks in a Bee's Wing 74 



Scales on a Gnat's Wing ..... v ,. 75 



