JCYIJ 



INDEX. 



Sight, how are defects in, detected 



by opticians ......... 130 



Skin, why has it a purple hue 



when cold ........... 35 



Skin, why are the pores essential 



to health ............ 101 



Skull, why the only cavity in the 



body not enclosed by a mem- 



brane ............ 53 



Skull, why may the form of be 



altered ............ 92 



Skylark, why does the song of 



vary ............... 758 



Sloth, why does it utter the sound 



of"ai' r ............ 404 



Sloth, why able to exist through 



winter without fond ...... 405 



Sloth, why well provided with 



means of defence... ...... 407 



Sloth, why erroneously considered 



awkward ... ...... 



408 

 410 



Sloth, why has it difficulty in 



walking on the ground ...... 



Sloth, how adapted to the locali- 



ties it inhabits ......... 413 



Sloth, habits and instincts of ... 415 

 Smell, how is the sense produced 151 

 Smell, why does sniffing air in- 



crease ............ 152 



Smell, why does closing the mouth 



increase ... ... ... ... 153 



Smelling, why are the organs of, 



situated so near those of tasting 154 

 Smell, why is the sense of, in dogs 



acute ............ 268 



Snake, how dons it throw its body 



from the ground ....... .". 1021 



Snake-catchers, why are they able 



to charm snakes ......... 1025 



Snipe, why has it a long tapering 



bill ............... 894 



Snipes, why are their eyes back- 



ward in their heads ...... 895 



Snipes, why do they not have long 



hind toes ............ 896 



Sole, why r'nes its skin clear 



coffee ............ 1092 



Soles, why are they destitute of 



air-bladders ......... 1093 



Soles, why do they swim upon 



their sides ............ 1096 



Solids, their effect upon the body 40 

 Solidungula, sol-id-ui>g'-c/u-la ... 473 

 Solid ungulous animals, why found 



in a wild state on plains ...... 475 



Souslik, sotcs'-lik, why has it 



pouches in its cheeks ...... 359 



Sparrows, why useful to vegeta- 



tion ............... 751 



Sparrows, why bolder than most 



birds ...... " ...... 752 



Sparrow, why does the house- 



sparrow take the nests of other 



birds ............... 753 



Sparrow, why late in awaking ... 754 

 Species, what is the meaning of ... Ki3 

 Spectacles, why needed in old age 129 

 Spermaceti, what is it ...... 587 



bpinal columr. why flexible ... 41 



Spine, why do not its movements 

 injure the brain 91 



Spoonbill, why has it long man- 

 dibles 905 



Sprats, what are they 1057 



Sprats, why do they usually ap- 

 pear soon after herrings have 

 spawned 1058 



Squinting, why some persons 

 afflicted 132 



Squinting, how cured 133 



Squirrels, why do they convey 

 food to their mouths with both 

 paws 351 



Squirrels, why grouped as the 

 genus sciurus 352 



Squirrels, why are their hind legs 

 only slightly shorter than their 

 fore legs 353 



Squirrels, why are their tails so 

 long and bushy 355 



Squirrels, why are their eyes fully 

 developed 354 



Squirrels, why they lay up stores 356 



Squirrels, why some called flying 358 



Stag, why so eager to reach water 

 before they stand at bay 527 



Stairs, why said to shed tears ... 535 



Starlings,' why do they frequently 

 accompany rooks ... ... ... 993 



Statue, why cannot stand upright 

 without support 17 



Stickleback, why ai-e the fins 

 nearest its gills continually 

 moving 1141 



Stomach, what is the form of ... 100 



Stork, why an enemy of the cat 

 species ' 907 



Storks, why are they voracious 

 eaters 908 



Stork, why has it always been an 

 object of favour and veneration 909 



Swallows, why appoint a distinct 

 range of elevation ... ... 712 



Swallows, why adapted to migra- 

 tion 713 



Swallows, why are the nests made 

 round 714 



Swallows, why their mandibles 

 open far back 726 



Swallows, how do they build 

 asninst walls 716 



Swallows, why do they build near 

 dwellings of man 717 



Swallow, why is the esculent, so 

 called " 719 



Swallows, why does their high 

 flight foretell fine weather ... 724 



Swans, -why do they frequent 

 shallow waters 928 



Swans, whv are their wings 

 capable of dealing a heavy blow 929 



Swans, why do they fly high ... 928 



Swans, whv is their flight governed 

 by the wind 933 



Swan, why is its plumage un- 

 changeable 9:;4 



Swan, why is its dying song 

 fu'oulous ... ... ... ... 9UJ 



