X.] PANGENESIS. 223 



CHAPTER X. 



PANGENESIS. 



A Provisional Hypothesis supplementing " Natural Selection. 11 Statement of the Hy- 

 pothesis. Difficulty as to Multitude of Gemmules. As to Certain Modes of Ee- 

 production. As to Formations without the Eequisite Gemmules. Mr. Lewes and 

 Prof. Delpino. Difficulty as to Developmental Force of Gemmules. As to their 

 Spontaneous Fission. Pangenesis and Vitalism. Paradoxical Reality. Pangene- 

 sis scarcely superior to Anterior Hypothesis. Button. Owen. Herbert Spen- 

 cer. " Gemmules 11 as Mysterious as "Physiological Units. 11 Conclusion, 



IN addition to the theory of " Natural Selection," by 

 which it has been attempted to account for the origin of 

 species, Mr. Darwin has also put forward what he modestly 

 terms " a provisional hypothesis " (that of Pangenesis), by 

 which to account for the origin of each and- every individ- 

 ual form. 



Now, though the hypothesis of Pangenesis is no neces- 

 sary part of " Natural Selection," still any treatise on spe- 

 cific origination would be incomplete if it did not take 

 into consideration this last speculation of Mr. Darwin, The 

 hypothesis in question may be stated as follows : That each 

 living organism is ultimately made up of an almost infinite 

 number of minute particles, or organic atoms, termed "gem- 

 mules," each of which has the power of reproducing itsf 

 kind. Moreover, that these particles circulate freely about 

 the organism which is made up of them, and are derived 

 from all the parts of all the organs of the less remote an- 

 cestors of each such organism during all the states and 

 stages of such several ancestors' existence ; and therefore of 

 the several states of each of such ancestors' organs. That 

 such a complete collection of gemmules is aggregated in 



