70 ON HEREDITY. 



not an exhaustive treatment of the subject could be given. 

 I have also abstained from giving further details in the form 

 of an appendix, chiefly because I could hardly have attempted 

 to complete a treatment of the w^hole range of the subject, and 

 I hope to refer again to these questions in the future, when 

 new experiments and observations have been made. 



I am very glad to see that such an important authority as 

 Pfliiger ^ has in the meantime come to the same opinion, from 

 an entirely different direction — an opinion which forms the 

 foundation of the views here brought forward, namely, that 

 heredity depends upon the continuity of the molecular sub- 

 stance of the germ from generation to generation. 



A. W. 



^ Pfliiger, ' Ueber den Einfluss der Schwerkraft auf die Theilung der 

 Zellen und auf die Entwicklung- des Embryo,' Arch. f. Physiol. Bd. 

 XXXII. p. 68, 1883. 



