36 THE EVOLUTION OF MAN. 



moving threads exist in the sperm or seminal fluid of the 

 male. (Cf, Fig. 17 in Chap. YII.) This astonishing discovery- 

 was at once interpreted to the effect that these minute 

 living bodies, briskly swimming about in the seminal fluid, 

 were genuine animals, the pre-formed germs of future 

 generations. When at the time of fecundation the two 

 generative substances, male and female, came in contact 

 with each other, these thread-like seminal animalcules were 

 to penetrate into the fruitful soil of the ovary and there to 

 attain their development like vegetable seeds in the fruitful 

 soil of the earth. According to this theory every single 

 seminal animalcule of Man is a complete human being; all 

 the separate parts of the body would be entirely pre-formed 

 in it, and subject only to a mere unwrapping and enlargement 

 as soon as they reached the favourable matrix of the female 

 egg. This theory also was logically carried out to the effect 

 that in every single thread-like body were contained all the 

 subsequent generations of its descendents, one encased in 

 the other, each in the most extreme degree of fineness, and 

 of the minutest size. The seminal gland of Adam, therefore, 

 contained the germs of all the children of men who have 

 ever peopled our planet, who inhabit it at present, or will 

 occupy it in the future " until the end of the world." 



Of course, this Doctrine of Encasement in the Male was 

 utterly opposed to the Doctrine of Encasement in the Female, 

 which had previously prevailed. The only ground common 

 to both was the false idea that the germs of innumerable 

 o-enerationS; previously formed and encased one in another, 

 existed in every organism ; a conception on which was also 

 founded the curious Prolepsis Theory of Linn?eus. 



The two opposite theories of encasement soon began a 



