Charles Darwin: On the Origin of Species & On the Tendency of Species to Form Varieties. Чарльз Дарвин

6. Multiple, Rudimentary, And Lowly-Organised Structures Are Variable

       7. A Part Developed In Any Species In An Extraordinary Degree Or Manner, In Comparison With The Same Part In Allied Species, Tends To Be Highly Variable

       8. Specific Characters More Variable Than Generic Characters

       9. Secondary Sexual Characters Variable

       10. Distinct Species Present Analogous Variations, So That A Variety Of One Species Often Assumes A Character Proper To An Allied Species, Or Reverts To Some Of The Characters Of An Early Progenitor

       11. Summary

       Chapter 6 Difficulties Of The Theory

       1.

       2. On The Absence Or Rarity Of Transitional Varieties

       3. On The Origin And Transition Of Organic Beings With Peculiar Habits And Structure

       4. Organs Of Extreme Perfection And Complication

       5. Modes Of Transition

       6. Special Difficulties Of The Theory Of Natural Selection

       7. Organs Of Little Apparent Importance, As Affected By Natural Selection

       8. Utilitarian Doctrine, How Far True: Beauty, How Acquired

       9. Summary: The Law Of Unity Of Type And Of The Conditions Of Existence Embraced By The Theory Of Natural Selection

       Chapter 7 Miscellaneous Objections To The Theory Of Natural Selection

       Chapter 8 Instinct

       1.

       2. Inherited Changes Of Habit Or Instinct In Domesticated Animals

       3. Special Instincts

       4. Instincts Of The Cuckoo

       5. Slave-Making Instinct

       6. Cell-Making Instinct Of The Hive-Bee

       7. Objections To The Theory Of Natural Selection As Applied To Instincts: Neuter And Sterile Insects

       8. Summary

       Chapter 9 Hybridism

       1.

       2. Degrees Of Sterility

       3. Laws Governing The Sterility Of First Crosses And Of Hybrids

       4. Origin And Causes Of The Sterility Of First Crosses And Of Hybrids

       5. Reciprocal Dimorphism And Trimorphism

       6. Fertility Of Varieties When Crossed, And Of Their Mongrel Offspring, Not Universal

       7. Hybrids And Mongrels Compared, Independently Of Their Fertility

       8. Summary Of Chapter

       Chapter 10 On The Imperfection Of The Geological Record

       1.

       2. On The Lapse Of Time, As Inferred From The Rate Of Deposition And Extent Of Denudation

       3. On The Poorness Of Palaeontological Collections

       4. On The Absence Of Numerous Intermediate Varieties In Any Single Formation

       5. On The Sudden Appearance Of Whole Groups Of Allied Species

       6. On The Sudden Appearance Of Groups Of Allied Species In The Lowest Known Fossiliferous Strata

       Chapter 11 On The Geological Succession Of Organic Beings

       1.

       2. On Extinction

       3. On The Forms Of Life Changing Almost Simultaneously Throughout The World

       4. On The Affinities Of Extinct Species To Each Other, And To Living Forms

       5. On The State Of Development Of Ancient Compared With Living Forms

       6. On The Succession Of The Same Types Within The Same Areas, During The Later Tertiary Periods