136 THE CASE AGAINST EVOLUTION 



procedures of sterilization and the basis of antiseptic surgery." 

 {Science, Dec. 14, 1923, p. 477.) Pasteur brought to a suc- 

 cessful completion the work of Redi and Spallanzani. Hence- 

 forth spontaneous generation was deprived of all countenance 

 in the realm of biological fact. 



Meanwhile, the cytologists and embryologists of the last 

 century were adding article after article to the law of genetic 

 cellular continuity, thus forging link by link the fatal chain of 

 severance that inexorably debars abiogenesis from the domain 

 of natural science. With the formulation of the great Cell 

 Theory by Schleiden and Schwann (1838-1839), it became 

 clear that the cell is the fundamental unit of organization in 

 the world of living matter. It has proved to be, at once, the 

 simplest organism capable of independent existence and the 

 basic unit of structure and function in all the more complex 

 forms of life. The protists (unicellular protozoans and proto- 

 phytes) consist each of a single cell, and no simpler type of 

 organism is known to science. The cell is the building brick 

 out of which the higher organisms or metists (i.e. the multi- 

 cellular and tissued metazoans and metaphytes) are con- 

 structed, and all multicellular organisms are, at one time or 

 other in their career, reduced to the simplicity of a single 

 cell {v.g. in the zygote and spore stages). The somatic or 

 tissue cells, which are associated in the metists to form one 

 organic whole, are of the same essential type as germ cells 

 and unicellular organisms, although the parallelism is more 

 close between the unicellular organism and the germ cell. 

 The germ cell, like the protist, is equipped with all the poten- 

 tialities of life, whereas tissue cells are specialized for one 

 function rather than another. The protist is a generalized and 

 physiologically-balanced cell, one which performs all the vital 

 functions, and in which the suppression of one function leads 

 to the destruction of all the rest; while the tissue cell is a 

 specialized and physiologically-unbalanced cell limited to a 

 single function, with the other vital functions in abeyance 

 (though capable of manifesting themselves under certain cir- 



