THE ORIGIN OF LIFE 141 



that the ultramicroscopic particles may have the same powers 

 and may be the sources or '^ formative foci" of the larger 

 formed bodies, which were hitherto thought to arise de novo. 



Certainly, pathology, as we shall see, tells us of ultramicro- 

 scopic disease-germs, which are capable of reproduction and 

 maintenance of a specific type, and experimental genetics 

 makes us aware of a linear alignment of submicroscopic 

 genes in the nuclear chromosomes, each gene undergoing peri- 

 odic division and perpetual transmission from generation to 

 generation. The cytologist, therefore, to quote the words of 

 Wilson, "cannot resist the evidence that the appearance of 

 a simple homogeneous colloidal substance is deceptive; that 

 it is in reality a complex, heterogeneous, or polyphasic sys- 

 tem. He finds it difficult to escape the conclusion, there- 

 fore, that the visible and the invisible components of the 

 protoplasmic system differ only in their size and degree of 

 dispersion; that they belong to a single continuous series, 

 and that the visible structure of protoplasm may give us 

 a rough magnified picture of the invisible." {Ibidem, p. 283.) 



It would seem, therefore, that we must restore to honor, as 

 the fifth article of the law of cellular continuity, the formula, 

 which Richard Altmann enunciated on purely speculative 

 grounds in 1892, but which the latest research is beginning to 

 place on a solid factual basis, namely: Omne granulum ex 

 granulo. 'Tor my part," says the great cytologist, Wilson, "I 

 am disposed to accept the probability that many of these parti- 

 cles, as if they were submicroscopical plastids, may have a 

 persistent identity, perpetuating themselves by growth and 

 multiplication without loss of their specific individual type." 

 And he adds that the facts revealed by experimental em- 

 bryology {e.g., the existence of differentiated zones of spe- 

 cific composition in the cytoplasm of certain eggs) "drive 

 us to the conclusion that the submicroscopical components 

 of the hyaloplasm are segregated and distributed according 

 to an ordered system." {Ibidem, p. 283.) The structure of 

 the cell has often been likened to a heterogeneous solution, 



