192 



INDEX. 



Nageli, 94. 



Natural selection, 104. 

 Nephridium, 132, 133. 

 Nerve-cells, 136, 159. 



action of, 139 

 Nerves, 136, 139, 140. 

 Nervous impulse, 139. 

 Nervous system, 136, 159. 

 Nettle, 29, 31. 

 Nitella, 28, 42. 

 Nucleolus, 50. 

 Nucleus, 16, 25, 49, 55. 

 Nuphar, 62. 



Nutrition, 104, 105, 124, 166. 

 Nymphcea, 62. 



(Esophagus, 125. 



Oophore, 89. 



Oosphere, 97. 



Optimum temperature, 40. 



Organic systems, 123. 



Organism, 13. 



Organs, 12. 



Origin of species, 104, 175. 



Outgo of Lumbricus, 164. 



of Pteris, 108. 

 Ova, 142, 143. 

 Ovaries, 142, 143. 

 Oviducts, 144. 

 Ovum, 49, 61. 



Parenchyma, 74. 

 Pelargonium, 42. 

 Peptones, 163. 



Peripheral nervous system, 138. 

 Peristaltic contraction, 129. 

 Peritoneal epithelium, 157. 

 Pharyngeal collar, 136. 

 Pharyngeal ganglia, 138. 

 Pharynx, 125. 

 Phloem-parenchyma, 75, 79. 



prosenchyma, 75. 



sheath, 78. 

 Physa, 61. 



Physical relations of protoplasm, 39. 

 Physiological division of labor, 51, 155. 

 Physiology, 7, 8. 



of animal, 102. 



of plant, 102. 



of the tissues, 109. 



Pinna, 68. 



Pinnatifid. 68. 



Pinnule, 68. 



Pits, in the cell-membrane, 57. 



scalariform, 79. 

 Planorbis, 61. 

 Poisons, 41, 47. 



Primary mesoblastic cells, 148. 

 Primordial utricle, 28, 55. 

 Proctodaeuin, 151. 

 Pronucleus, 146. 

 Prosenchyma, 74. 

 Prostomium, 121. 

 Proteids, 3, 4, 35, 43, 167, 178. 



digestion of, 163. 



in the plant, 107. 

 Proteus animalcule, 26. 

 Prothallium, 89. 

 Protonema, 93. 

 Protoplasm, 4, 5, 16, 23. 



manufacture of, 107, 163. 



vegetal and animal, 41. 

 Pseudhaemal, 128. 

 Pscudopod, 26. 

 Psychology, 8, 9. 

 Pteris, biology of, 64. 



Receptacle, 90. 



Reflex action, 6, 139. 



Relation, 124. 



Reproduction, 3, 4, 88, 110, 124. 



of Lumbricus, 140. 



of Pteris, 89. 

 Respiration, 124, 134. 



of Lumbricus, 134. 



of Pleris, 108. 

 Respiratory system, 134. 

 Rhizoids, 81, 93. 

 Rhizome, 67, 69, 71, 73. 

 Rigor caloris, 40, 46. 

 Rigor mortis, 46. 

 Ritthausen, 36. 

 Root-cap, 81. 

 Roots, 80. 

 Rotation of protoplasm, 26, 27. 



Sachs, 73, 179, 180. 

 Sap, 11, 28, 105. 

 Sarcode, 23. 



Schleiden, 48. 



