CONTENTS. XI 



Page 



On the Bug [ Cimex lectularms] 103 



On the External Characters of Insects 104 



On the Senses of Insects 104 



On the Nourishment of Insects 105 



Of the Store or Fat of Insects 105 



Of the Food of Insects 105 



Of the Digestion of Insects 106 



Of the Teeth of Insects 106 



Of the Weapons of Insects 106 



Of the Heart and Blood of Insects 107 



Of the Circulation in Insects 107 



Of the Respiratory Organs of Insects 108 



Of the Water Spider [Hydrachna] 108 



On the River Crawfish [Astacusjhiviatilis] 109 



On the Earthworm [Lumbricus terrestris] 109 



On the Geographical Distribution of Animals Ill 



OBSERVATIONS ON PHYSIOLOGY. 



Of Life and the Living Principle. 



Analogy of Life to Combustion 113 



Living Principle, its union with Body 114 



Living Principle, its Nature and Degrees 114 



Living Principle, illustrated by the mutual attraction of Parts for union 115 



Of Simple Life 115 



Loss of Simple Life 118 



Degrees of Simple Life 118 



Action adverse to Simple Life 118 



Degrees of Excitements and Sedatives 119 



On Animal Heat 120 



On Respiration 1 121 



On the Blood 126 



On the Circulation 126 



Of the Arteries 127 



Of the Veins 127 



Of the Absorbents ' 128 



Of the Heart 2 128 



Of the Uses of Arteries 132 



Of the Vitality of Arteries 133 



Of the Origins of Arteries 133 



Of the Food 135 



Of the Teeth 3 137 



Reasons for a space between the Cutters and Grinders of Quadrupeds 140 



1 [An extract from this MS. had been prefixed by Hunter to the MS. Catalogue 

 transferred with the Collection to the Museum of the Royal College of Surgeons, 

 and is printed in the Physiological Catalogue, vol. ii. p. 66.] 



-' [lb. vol. ii. p. 25.] 3 [lb. vol. i. p. 77.] 



