ILLUSTRATIONS. 



T1GE 



Tree-toads Frontispiece 



" Bright Dots of Goldfinches " ... 15 



The Great Carolina Wren ..... 26 



The Retreat of the Towhee 29 



Blarina — the Short-tailed Shrew ... 33 

 Skull of a Shrew (magnified), showing 



Character of the Teeth ..... 35 

 Neosorex — the Long-tailed Shrew . . 37 

 " The Edge of a Brook in the Country " 40 

 "Pebbly Shallows just above the Cata- 

 ract " 45 



Brook Blossoms 48 



Moths 53 



Trying its Wings 54 



The Struggle for Existence in Winter . 59 



Thick-shelled Paludinse 62 



Partridges in Winter 69 



A Vigilant Hare 71 



After a Sleet Storm 73 



The Fox's Winter Prey 75 



Alexander Agassiz 79 



Materials for Laboratory Study ... 89 



A Typical Rattlesnake 93 



Head of the Copperhead — upper and 



under views 95 



Head of the Copperhead— side and face 



views 95 



Cranium of Crotalus, with Muscles con- 

 cerned in the Venom Stroke . . . .103 



PAGE 



Bones of the Upper Jaw 103 



Relation of Temporal Muscles to the 



Gland ... 104 



Oyster's Egg, immediately after Fertili- 

 zation 113 



Egg three Hours after Fertilization . . 114 

 Egg at a Later Stage ... ... 114 



Egg in its Final Stage 114 



First Appearance of the Embryo . . 115 

 An Oyster One Year Old, showing Em- 

 bryonic Shell at the Apex, and Lines 

 of subsequent Additions . . . 115 



The Slipper Limpet 118 



Star-fishes (lower figure showing under 



side and ambulacra) 121 



Egg of the Star-fish, after Fertilization . 124 

 An Egg nearly ready to Hatch . . 124 

 An Embryo Star-fish at an early Stage, 

 seen edgewise ... .... 124 



A more advanced Embryo, swimming 

 by Rows of Cilia along the Protuber- 

 ances . 125 



A Young Star-fish 125 



Dining upon an Oyster 129 



Reproducing four lost Arms .... 133 



Shell of Fulgur carica 138 



A " Sea-necklace " — Egg-cases of Fulgur 140 



Sycotypus canaliculars 141 



Purpura lapillus 145 



