of course it still possesses these powers, since it has remained dormant without alteration.  Further, it will follow that if this dormant undifferentiated chromatin should start into activity and produce a new individual, the new individual thus produced would be identical in all characters with the one which actually did develop from the egg, since both individuals would have come from a bit of the same chromatin.  The child would be like the parent.  This would be true no matter how much this undifferentiated material should increase in amount by assimilation, so long as it remained unaltered in character, and it hence follows that every individual carries around a certain amount of undifferentiated chromatin material in all respects identical with that from which he developed.

Now whether this undifferentiated germ plasm, as we will now call it, is distributed all over the body, or is collected at certain points, is immaterial to our purpose.  It is certain that portions of it find their way into the reproductive organs of the animal or plant.  Thus we see that part of the chromatin material in the egg of the first generation develops into the second generation, while another part of it remains dormant in that second generation, eventually becoming the chromatin of its eggs and spermatozoa.  Thus each egg of the second generation receives chromosomes which have come directly from the first generation, and thus it will follow that each of these eggs will have identical properties with the egg of the first generation.  Hence if one of these new eggs develops into an adult it will produce an adult exactly like the second generation, since it contains chromosomes which are absolutely identical with those from which the second generation sprung.  There is thus no difficulty in understanding why the second generation will be like the first, and since the process is simply repeated again in the next reproduction, the third generation will be like the second, and so on, generation after generation.  A study of the accompanying diagram will make this clear.

In other words, we have here a simple understanding of at least some of the features of heredity.  This explanation is that some of the chromatin material or germ plasm is handed down from one generation to another, and is stored temporarily in the nucleii of the reproductive cells.  During the life of the individual this germ plasm is capable of increasing in amount without changing its nature, and it thus continues to grow and is handed down from generation to generation, always endowed with the power of developing into a new individual under proper conditions, and of course when it does thus give rise to new individuals they will all be alike.  We can thus easily understand why a child is like its parent.  It is not because the child can inherit directly from its parent, but rather because both child and parent have come from the unfolding of two bits of the same germ plasm.  This fact of the transmission of the hereditary substance from generation to generation is known as the theory of the continuity of germ plasm.