CHAPTER V.

DEVELOPMENT.

Nature of inquiry stated, 154 158

_Chemical development_— Changes in lists of elementary substances, 155 159 Prout’s speculations, 156 160 Experiments of M. Stas, 156 160 Family groups, 157 161 Mr. Lockyer’s speculations, 158-159 161

_Globe development_— Hypothesis of Kant and Laplace, 160 163 Tendency to aggregation of mass, 161-162 164 Process cannot have been going on for ever, 163 166 Peculiarity of products developed inorganically, 164 167

_Life development_— Morphological and physiological species, 165 168 Species regarded physiologically, 166 170 Position of a certain class of theologians, 167 171 Tendency to minor variations, 168 172 Artificial selection, 169 174 Natural selection, 170 175 Unproved point in the Darwinian hypothesis, 171 175 Remarks of Mr. Darwin, 172 177 Development of the Darwinian hypothesis, 173 177 Mr. Wallace’s views, 174 178 Professor Huxley’s remarks, 175 178 Position assumed by the authors, 176 179