“You mean,” I said, “that the occasional reversions to the earlier form convey some material suggestion?”

“Yes; but more than that. What we learn from an inspection of this series is this: that there was a change in the character of the signature; a very slight change, but quite recognizable. Now that change was not gradual or insidious nor was it progressive. It occurred at a certain definite time. At first there were one or two reversions to the earlier form, but after number six the new style continued to the end; and you notice that it continued without any increase in the change and without any variation. There are no intermediate forms. Some of the signatures are in the ‘old style’ and some in the ‘new,’ but there are none that are half and half. So that, to repeat: We have here two types of signature, very much alike, but distinguishable. They alternate, but do not merge into one another to produce intermediate forms. The change occurs abruptly, but shows no tendency to increase as time goes on; it is not a progressive change. What do you make of that, Jervis?”