NUCLEUS AS SOURCE OF ENERGY 157 



does it appear that tlie missing links between the 

 organic and the inorganic are to be accounted for. 

 Haeckel has regarded the Monera — or rather a 

 particular type of Monera, called Cromacea — as 

 the most primitive of all organisms known to us. 

 They are, as we have said, supposed to be structure- 

 less organisms, and to have no visible organisation 

 or composition from different organs. These cells 

 without nuclei have, as he points out, been ignored 

 and neglected by most biologists. But. the existence of 

 cells without nuclei is considered extremely doubtful, 

 and although they may appear to be quite structure- 

 less it is more than probable that the structure 

 has merely escaped our notice owing to imperfections 

 either in the methods of staining or in the optical 

 arrangements. As has been suggested already, the 

 cell may be a nucleus itself without any cytoplasm. 



The view herein put forward, however, is that 

 they constitute merely one of the many missing 

 links we are in search of, and that they are far 

 more complicated than any artificial types which 

 we can endeavour to produce. In these gaps 

 there exist, between the organic plasma products 

 and inorganic crystals, types called bio-crystals 

 which are formed by the interaction of mineral 

 matter and plasm.. Amongst these we may men- 

 tion the crystalline flint and chalk skeletons of 

 the sponges and corals, and, as Haeckel points out, 

 it is also in the flinty shells of the diatoms and 

 radiolaria. His idea, however, like that of Schleiden 

 and Schwann, that crystals are also types of elementary 



