THE PRESIDENT'S ADDRESS. 269 



Monera," says Haeckel, "is throughout life nothing more than a 

 motile lump of slime without constant form, a small living bit of 

 an albuminoid carbon compound. We agree that this homogeneous 

 mass possesses a very complex minute molecular structure ; but 

 this is not anatomically or microscopically demonstrable. Simpler, 

 less perfect organisms are not thinkable." * 



Recent researches, unfortunately, tend to throw considerable 

 doubt upon the existence of such Monera. It has been pointed 

 out that the failure to recognise a nucleus may have been due to 

 the imperfections of microscopical technique at the time when the 

 organisms in question were described. Even some of the Bacteria, 

 which Haeckel regarded as Monera and which are amongst the 

 smallest recognisable organisms, are now known, as we have just 

 seen, to exhibit well-marked differentiations in their protoplasm, 

 and many of the supposed " cytodes " or unnucleated cells, have 

 already been shown to possess a nucleus. With regard to others 

 the matter must be regarded as still sub judice. 



Haeckel himself, it must be remembered, recognised the fact 

 that his Monera must be composed of ultra-microscopic molecules 

 or groups of molecules, which he spoke of as Plastidules or 

 Micellae, the latter term having been coined by Naegeli. 



It is these ultra-microscopic and indeed purely hypothetical 

 particles of colloidal proteid that the modern biologist is inclined 

 to regard as representing the most primitive living organisms, 

 and Weismann has gone so far as to assign to them a definite 

 place in our scheme of classification, proposing for their recep- 

 tion the so-called family Biophoridae and identifying them with 

 the biophors or ultimate vital units of his well-known theory 

 of heredity. 



It has further been pointed out that such minute particles of 

 living matter, far smaller than the most minute Bacteria, may be 

 arising all around us by so-called spontaneous generation at the 

 present day, without our being able to recognise the fact. It is 

 only when, in the course of evolution, they had become aggregated 

 in relatively large masses, that we could hope to see them even 

 with the highest powers of our microscopes. The justice of this 

 view might, however, fairly be questioned. When chemical mole- 

 cules arise in our laboratories by combination of atoms or of 



* Translated from Haeckel's " Schopfungsgeschichte," Edition 9 (1898), 

 p. 165. 



