538 THE BEGINNINGS OF LIFE. 



distributed through the atmosphere, and, indeed, he 

 would be a rash man who would promise to find a single 

 one oi such easily recognizable bodies amongst the 

 products of filtration from the atmosphere, obtained by 

 a week's work. The Panspermic hypothesis, indeed, 

 breaks down even more utterly with regard to the germs 

 of these comparatively high organisms than it does with 

 reference to the distribution of Bacteria (pp. 6, 7). But 

 although the almost universal distribution of Rotifers, 

 Tardigrades, and Nematoids cannot be at all accounted 

 for by those who rely simply upon Homogenesis and 

 the supposed universal distribution of the germs of 

 these and other organisms, all the facts may be easily 

 explained by an acceptance of the reality of such 

 heterogenetic processes as we have already described. 

 Heterogenesis is, in fact, the necessary appanage of 

 Archebiosis — so that the reality of the one process 

 almost necessitates the reality of the other. 



The importance of an adequate consideration of 



was not systematically examined at the time. I was much impressed, 

 however, by the facts which were then wholly inexplicable to me — and 

 as such I recollect mentioning them soon after to two or three eminent 

 biologists. These observations were made very shortly before I left 

 Broadmoor, and since that period the great pressure of other kinds of 

 work has always prevented my following up this observation by new 

 experiments. These, however, had been contemplated, and I had 

 intended to resort to comparative trials of different kinds of meat mixed 

 with similar specimens of earth and water, and at the same time to 

 subject these mixtures to careful and daily microscopical examinations. 

 Experiments and observations of this kind, which still have to be made, 

 would, I have no doubt, soon lead to most important results. 



