78 ADAPTATION AND DISEASE 



chromatin. We cannot help being impressed by the extra- 

 ordinary sequence of events all tending to this end result. No 

 other element common to the two germ cells is partitioned out 

 so meticulously. There is no other element common to the 

 two cells that is doled out with the same equivalence. Next, 

 making a careful survey of heritable and inherited properties, 

 we are forced to the conclusion that the likelihood is equal, 

 that the offspring inherits either from the male or from the 

 female parent. The conclusion is inevitable that the biophoric 

 molecules are conveyed in and by the nuclear chromatin. In 

 the bacteria which are so lowly that they possess no central 

 nucleus we observe nevertheless that chromatin-like granules 

 are scattered through the body substance, and that in 

 binary division these chromatin- 

 like granules undergo a certain 

 simple accumulation or arrange- 

 ment, to the end that each of 

 the daughter cells is endowed 

 with half of this specific chromatin- 

 like material. 

 PIO. 4.-Ceii ^ndergdng mitosis ; Or otherwise, whereas in these 



skein stage to show the duplica- lowest forms the living Cell Sub- 

 tion of the chromatin thread j t -\ 



with beading of the same, which stance is made up of granules 

 is seen in some species. Weis- o f chromatin, each surrounded 



mann regarded these heads or , ;. , ,. , 



chromomeres (Id) as represent- bv an area oi cytoplasm, higher 



ing his ids. c , centrosome ; up m the scale these granules of 

 cyt, cytoplasm. -, . -. i, -, 



biophoric matter are collected into 



a central node, the nucleus, which is separated from the 

 circumambient external medium by the cytoplasm or cell 

 body. We may indeed speak of a triple protection, namely 

 the cell wall or membrane, the cytoplasm, and the nuclear 

 membrane, all of them on the whole acting as conservative 

 agents, tending to preserve the biophores from sudden change 

 from without. 



VITAL PROCESSES OF THE CELL 



But to continue, as it were, to rehearse our catechism, 

 while on the whole conservative, this system is exposed to con- 

 stant change, owing to the fact that it is not inert but is constantly 



