AT THE UNIVERSITY 79 



been declared to evolve by a kind of spontaneous 

 generation from the contents of the intestines. 

 But this also was proved to be untrue. Thus 

 there was ample material for a solid dogma : there 

 was no such thing as spontaneous generation. 

 The dogma, moreover, harmonised with the pre- 

 vailing belief in a special vital force and a radical 

 distinction between the living and the dead, which 

 was still shared in a subtle form by even a man 

 like Miiller. The dogma was formulated. Spon- 

 taneous generation was struck out of the scientific 

 vocabulary as unscientific and a popular super- 

 stition. The young doctor, duly initiated into these 

 ideas of the time, could not resist the temptation 

 to give his own kick to the fallen theory. Yet 

 how strangely things have changed since then ! 

 Two years afterwards Haeckel ceased to believe 

 in a special vital force; he was now absolutely 

 convinced that there were unicellular beings ; his 

 whole theory of life seemed to demand spontaneous 

 generation as a postulate, and he even doubted 

 the force of the experiments of Schwann and 

 others. Haeckel himself became the keenest 

 apostle of the theory of spontaneous generation. 

 Whenever it is mentioned to-day, we think of the 

 weight of his name which he has cast in the scale 

 in its favour. So the leaves change even in the 

 forest of science : yesterday green, to-day red and 

 falling, to-morrow green once more. On the same 

 branch as the dogmas we find the correctives 

 growing, that will at length split them open and 

 cast them as empty husks to the ground. 



