Peirce on existence and reality

In Cornelis de Waal, Peirce: A Guide for the Perplexed, it was written that Peirce has distinguished between real and existing. On biosemiotics list, Gary Richmond has recommended Kelly Parker’s, The Continuity of Peirce’s Thought on this subject. He has also quoted Peirce:

[. . .] I call your attention to the fact that reality and existence are two different things.”

Existence [. . .] is a special mode of reality, which, whatever other characteristics it possesses, has that of being absolutely determinate. Reality, in its turn, is a special mode of being, the characteristic of which is that things that are real are whatever they really are, independently of any assertion about them. If Man is the measure of things, as Protagoras said, then there is no complete reality; but being there certainly is, even then. ” CP 6.349

[. . . ] It will not be necessary to go into that question, which is one of great delicacy. It will be sufficient to point out certain respects in which reality and existence differ. Let us suppose two seeds to be exactly alike. I do not say that two seeds ever are so; but we are now merely considering the meanings of two words, and, therefore, we are free to imagine any state of things we can. We will suppose, then, that not merely to our senses, but to any conceivable senses, those seeds are precisely alike, except that they are in different places. But now we will suppose that I am really resolved to plant those two seeds in such different soil, and to treat them so differently, that they will grow into plants whose flowers will have different colors. They really will be different, whatever anybody may say or think. I have made certain dispositions, so that I myself could not now have it otherwise. Their future difference is then a reality, already. For the time has already passed at which anybody’s dictum could make the fact otherwise. Yet I have not decided what the colors of the flowers of each are to be; for one of the two seeds will be taken at random, and placed in one soil and the other in another. Now, when it comes to the existence of those flowers, the colors will be absolutely what they will be. There can be no uncertainty or ambiguity about existence. The reality, however, of my determination of the colors is not altogether certain.” CP 6.349