Chapter 8

_HOMOLOGIES._

Animals made up of parts mutually related in various ways.--What homology is.--Its various kinds.--Serial homology.--Lateral homology.--Vertical homology.--Mr. Herbert Spencer's explanations.--An internal power necessary, as shown by facts of comparative anatomy.---Of teratology.--M. St. Hilaire.--Professor Burt Wilder.--Foot-wings.--Facts of pathology.--Mr. James Paget.--Dr. William Budd.--The existence of such an internal power of individual development diminishes the improbability of an analogous law of specific origination ... _Page_ 155