CHAPTER XIII.

MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY: EMBRYOLOGY: RUDIMENTARY ORGANS.

CLASSIFICATION, groups subordinate to groups--Natural system--Rules and difficulties in classification, explained on the theory of descent with modification--Classification of varieties--Descent always used in classification--Analogical or adaptive characters--Affinities, general, complex and radiating--Extinction separates and defines groups--MORPHOLOGY, between members of the same class, between parts of the same individual--EMBRYOLOGY, laws of, explained by variations not supervening at an early age, and being inherited at a corresponding age--RUDIMENTARY ORGANS; their origin explained--Summary

411-458