X.] PAXGEXESIS. 223 



CHAPTER X. 



PANGENESIS. 



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

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

 prodnction. As to Formations without the Requisite Gemmules. Mr. Lewes and 

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

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

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

 cer. " Gemmules " as Mysterious as "Physiological Units." 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 JPangenesis) J '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 maybe 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 its 

 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 



