HAECKEL AND PFLUGER 77 



the Earth are no longer appropriate. This idea was formu- 

 lated with special precision during the second half of last 

 century by the distinguished German scientist E. Haeckel 

 in his theory of archegony.^ 



The views of Haeckel and Pfliiger. 



Haeckel was a convinced and militant supporter of the 

 so-called monistic concept of the world which denied that 

 there was any essential difference between organisms and 

 inorganic bodies. "All natural bodies with which we are 

 acquainted on the Earth," he wrote, " both the animate and 

 the inanimate, are similar to one another in all the essential 

 properties of matter. Life is already present in the atom." 

 Thus, although the primary origin of living things had still 

 not been demonstrated by direct experiment it nevertheless 

 seemed indubitable, ' the logical postulate of natural philo- 

 sophy '. 



The hypothesis that the germs of life travelled through 

 interplanetary space cannot explain the appearance of life 

 on the Earth. However, as there was a time when the Earth 

 was in such a state that living things could not possibly 

 have inhabited it, organisms must have arisen from inert 

 matter at some time since this stage of the development of 

 the Earth. This is not inconsistent with the fact that we 

 cannot, at present, observe the spontaneous generation of 

 microbes. The development of organisms from lifeless matter 

 was perfectly possible at remote periods in the existence 

 of our planet, because special conditions prevailed then 

 which were different from the conditions obtaining now. 

 According to Haeckel it would seem that the primaeval 

 organisms must have been completely homogeneous, struc- 

 tureless, formless lumps of protein. They developed directly 

 bv the simple interaction of solutions in the primaeval sea 

 of matter.^" 



Haeckel did not explain how this development took place. 

 He even took the view that 



any detailed hypothesis whatever concerning the origin of 

 life must, as yet, be considered worthless, because, up till now, 

 we have not any satisfactory information concerning the ex- 



