Chap. XXVII. OF PANGENESIS. 399 



cellular organism. Reversion depends on the transmission 

 from the forefather to his descendants of doimiant gemmules, 

 which occasionally become developed under certain known or 

 unknown conditions. Each animal and plant may be com- 

 pared with a bed of soil full of seeds, some of which soon 

 germinate, some lie dormant for a period, whilst others 

 perish. When we hear it said that a man carries in his 

 constitution the seeds of an inherited disease, there is much 

 truth in the expression. No other attempt, as far as I am 

 aware, has been made, imperfect as this confessedly is, tc 

 connect under one point of view these several grand classes- 

 of facts. An organic being is a microcosm — a little universe, 

 formed of a host of self- propagating organisms, inconceivably 

 miriute and numerous as the stars in heaven. 



