GENEOLOGICAL. 371 



it were, the traditions of the race from which they have 

 sprung, and handing them on to their descendants." * 



Fertilisation. In his 49th Exercitation on " the 

 efficient cause of the chicken," Harvey thus quaintly 

 expressed what was to him, as it is to us, a baffling 

 problem : "Although it be a known thing subscribed 

 by all, that the fretus assumes its original and birth 

 from the male and female, and consequently that the 

 egge is produced by the cock and henne, and the 

 chicken out of the egge, yet neither the schools of 

 physicians nor Aristotle's discerning brain have dis- 

 closed the manner how the cock and its seed doth 

 mint and coine the chicken out of the egge." 



Even after Spallanzani had shown experimentally 

 (1786) that the fertilising power must be in the 

 minute spermatozoa, since filtered spermatic fluid 

 of frogs was inoperative, vague and even absurd views 

 continued to abound. 



" Even von Baer (1835) was inclined to interpret 

 the spermatozoa as minute parasites peculiar to the 

 male fluid ; Johannes Miiller seems also to have been 

 in doubt; and Richard Owen included them in his 

 article on * Entozoa ' (internal parasites) in Todd's 

 Cyclopaedia of Anatomy and Physiology" f In 1843 

 Martin Barry saw the union of sperm and ovum in 

 the rabbit, but it was not till 1854 that Bischoff 

 abandoned the theory that a mere touch of sperm and 

 ovum was sufficient to ensure fertilisation. 



In fact, the distinctively modern period in the 

 study of fertilisation only began about a quarter of 

 a century ago, when the researches of Auerbach, E. 

 van Beneden, Biitschli, Fol, De Bary, Strasburger, 



* E. B. Wilson, op. cit., p. 10. 

 f Thomson, Science of Life, p. 125. 



