DEVELOPMENT OF LIVING MATTER. 



55 



The size of a living body is not included in the definition 

 of an organized individual. In the infusion, f. i., we see 

 growing granules, just perceptible to the highest magnifying 

 powers of the microscope, in a fluid in which none were seen 

 a short time before. The smallest individuals which we are 

 capable of seeing with the best microscopes of to-day, are 

 granules ; but we must admit that germs or particles of living 

 matter may be present in the air or in fluids in infinite numbers, 

 which cannot be seen at all, and become visible only after having 

 attained a certain size. How complicated the structure of a 

 minute particle of living matter may be, we can hardly imagine ; 

 what we do know is, that the so-called "cell" is composed of 

 innumerable particles of living matter, every one of which is 

 endowed with properties formerly attributed to the cell-organism. 



The observation of the phases of development of the living 

 matter demonstrates that the term " cell " was attached to only 

 a limited number of forms, during the changes that take place 

 in a growing granule of a substance known to be the seat of 

 life. As the term "protoplasm" was adapted to the original 

 idea of the cell, it also meant only one or a few phases in the 

 development of a lump of living matter. (See Fig. 19.) 







FIG. 19. DIAGRAM OF THE PHASES OF DEVELOPMENT OF THE 

 LIVING MATTER. 



L, series of development of a small granule, a, into a vaouoled lump, b and c, and into a 

 frame-work, d. P, series of development into protoplasm of a reticular structure ; the so-called 

 " cell," e, with a solid, /, g, Ji, with vacuoled nuclei. B, series of development tending toward 

 the formation of basis-substance ; in i, the nucleus reticular, the nucleolus solid ; in fc and I, 

 the nucleolus splitting; and in m, the original granule a transformed into a finely reticular 

 mass, destitute of nucleus and nucleolus. 



