126 The Science of Life. 



the male organs or testes; in 1843 Martin Barry, an 

 Edinburgh medical student, saw the union of sperm 

 and ovum in the rabbit; in 1865 Schweigger-Seidel and 

 La Valette St. George showed that the spermatozoon 

 has a nucleus like other cells. Thus gradually was the 

 simple fact demonstrated that the spermatozoon is a cell. 

 Subsequent research has been concerned with studying 

 the structure of the sperm, its mode of origin, and its 

 behaviour in fertilization. 



In his forty-ninth exercitation, on "the efficient cause 



of the chicken", Harvey thus quaintly expresses what 



has always been, and still is, a baffling" pro- 



Fertilization. , - ff \i>\ 1-1 1 1-1 



blem : "Although it be a known thing sub- 

 scribed by all, that the foetus 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 coin the chicken out of the egge ". 



Baffling as the problem remains, it must be granted 

 that great progress has been made in the later years of 

 the Victorian era; many hundreds of researches directly 

 bearing on fertilization have been published since 1875; 

 the visible phenomena have been described in detail in 

 a multitude of cases; and we have become much more 

 definite as to what we wish to know. 



On the old views as to the nature of fertilization we 

 need not dwell; they were mere opinions without ade- 

 quate basis of facts. Some said the ovum was all- 

 important, and that the sperm merely supplied the 

 awakening touch; others said that the sperm was all- 

 important, and that the ovum merely supplied the 

 necessary nutriment; and even when both elements 

 were recognized as essential, vague ideas prevailed as 

 to the nature of fertilization. De Graaf believed in an 

 "aura seminalis" or seminal breath which passed from 

 the male fluid to the ovum, and until 1854 Bischoff 

 clung to the theory (which he then abandoned) that a 

 mere touch of sperm and ovum was sufficient to ensure 

 development. 



