One fact stands out prominently with reference to these pipes, and it is that any one who is familiar with conditions under which pipes are found can distinguish the prehistoric from the modern in most instances. Of course there are exceptions. Many modern pipes show the marks of steel tools, whereas the ancient forms do not. Certain specimens appear to those who have done a great deal of field work as ancient, whereas others do not. This is not merely a matter of opinion. I have found it very difficult, during my lifetime, to make those observers who have no intimate knowledge of field conditions realize the importance of this statement. There is no convenient formula whereby one may explain to a skeptic, how one specimen appears old and another does not. I shall consider this subject at greater length in the Conclusions. [Illustration: FIG. 435. Peculiar tube pipes. Collection of G. A. West, Milwaukee, Wisconsin. Tubular and trumpet-like pipes are shown in Figs. 427–28, and 430. These are considered to be earliest forms. More complicated tubes are observed in Fig. 435. Mr. West described these in his paper, previously cited. ] Various remarks offered here and there on the pages of this chapter may be taken to represent my conclusions as to pipes. I have not offered a summary at the end of the chapter, preferring to state pertinent observations, suggested by the figures illustrating pipes, as they occur. [Illustration: FIG. 436. (S. 2–3.) Onyx pipe-bowl with wooden stem. From cave-house ruins in San Juan County, Utah, February, 1894. The pipe lies against a fragmentary skin covering or robe. Henry Montgomery, Toronto, Ontario. ] [Illustration: FIG. 437. (S. 1–2.) Diminutive Siouan pipes. Collection of G. A. West, Milwaukee, Wisconsin. ] Of the fifteen types named by Mr. McGuire, the tubular, rectangular, and slightly curved pipe (of the forms shown in Fig. 433), are most common and widespread in the United States. As some years have elapsed since Mr. McGuire’s paper was written, monitor pipes in numbers have been reported from Wisconsin, Illinois, and Indiana. [Illustration: FIG. 438. (S. 1–2.) Peculiar stone pipe. Collection of H. M. Whelpley, St. Louis, Missouri. ] [Illustration: FIG. 439. (S. 1–2.) Vase-shaped pipe. John Weber’s collection. “Found by Mr. John Weber, in Killare, Juneau County, Wisconsin, in 1895, is of a pinkish-colored stone, and exhibits on its two opposite faces etched figures of some animal, possibly a lizard. The figure is after a sketch furnished by Mr. W. H. Elkey.” ] [Illustration: