May 5, 1899.] 



SCIENCE. 



639 



pearing. Four-nippled lambs increased 

 from n% in 1890 to 92% in 1895, since 

 which time the percentage has gradually 

 fallen, the four-nippled lambs being re- 

 placed by five and six-nippled lambs. The 

 first six-nippled lamb was born in 1896, 

 and the percentage has increased from 4% 

 in 1896 to 20% in 1899. 



Dr. Bell claimed that his statistics showed 

 that he had produced by selection a breed 

 of sheep possessing supernumerary mammae 

 as a normal condition. 



Figures are given on Plate V. show- 

 ing the normal milk- bag of a ewe, extra 

 nipples occurring as sports and the extra 

 nipples obtained by selective breeding. 



LATEST VOLCANIC ERUPTIONS OF THE PA- 

 CIFIC COAST. 



The date of the last volcanic eruption on 

 the Pacific coast of the United States, ex- 

 clusive of Alaska, has long been a matter of 

 doubt, and will probably remain so for 

 many j'ears to come. Speaking geologic- 

 ally, much of the material in the great vol- 

 canic field of the Northwest, including a 

 large part of Oregon and Washington, with 

 portions of California, Idaho and Wyo- 

 ming, is of comparatively recent eruption. 

 The outbursts may have begun in the Eo- 

 cene, were most violent and extensive dur- 

 ing the Miocene and Pliocene, and, dimin- 

 ishing in vigor, extended, perhaps, up to the 

 borders of the historical period. In Alaska, 

 however, there have been eruptions from 

 Bogoslov, St. Augustin and other volcanoes 

 as late as 1883 and even later, and there 

 can be no question concerning the reliabil- 

 ity of the testimony. G. F. Becker gives a 

 list (U. S. G. S., 18th Ann. Eept., Part III., 

 p. 14) of over forty volcanoes in Alaska 

 which have been reported active within his- 

 torical times. 



The evidence, so far as the Pacific States 

 are concerned, is given chiefly by Professor 

 J. D. Whitney (The United States, 1889, p. 



114), Major C. E. Button (Science, Vol. 

 VI., p. 46), Professor George Davidson 

 (Science, Vol. VI., p. 262), and Dr. H. A. 

 Harkness, (Proc. of the Cal. Acad, of Sci., 

 Vol. v., p. 408). Although there are no 

 new facts at hand definitely fixing the date 

 of the last eruption in that region, there 

 has recently come to my attention some in- 

 formation having a bearing upon other evi- 

 dence. 



Last summer Mr. Frederick V. Coville, 

 Botanist of the Department of Agriculture, 

 while studying the flora of Mt. St. Helens, 

 in Washington, found some interesting 

 fragments of charcoal, which he transmitted 

 to the Director of the U. S. Geological Sur- 

 vey, with the following letter: 



"I collected two pieces of coniferous charcoal at 

 the point where the trail from Lake Merrill to Mt. St. 

 Helens crosses the Kalama River. Each came from a 

 short charred piece of tree trunk about two feet long 

 and a foot in diameter. My attention was first called 

 to them by Colonel J. J. Hawkins, of Portland. The 

 pieces of charcoal were caught with other fresh drift 

 material brought down the Calama from Mt. St 

 Helen's in last spring's flood. They were charred 

 all the way to the center as evenly and thoroughly as 

 the fragments sent you. 



" The character of the charcoal, which need not be 

 described in detail here, is such as at first to suggest 

 that it was made in a very carefully prepared kiln. 

 There are, however, no charcoal pits in the region, 

 and the charcoal from forest fires has a very different 

 character. It is evident from the peculiarities of the 

 flora of Mt. St. Helens, and from its limited erosion, 

 that it is a mountain of very recent volcanic origin. 

 Among other phenomena presented by it was one 

 which, although it did not come under my own ob- 

 servation, is well substantiated by people of the re- 

 gion, and furnishes an explanation of the pecnliar 

 sections of charred logs found at the crossing of the 

 Kalama. The phenomena described is the occurrence 

 of molds of tree trunks at various points in the lava 

 flows about the base of Mt. St. Helens. In some 

 places these molds occur in large numbers and lie in 

 the beds in either a horizontal or a vertical position. 

 They are sometimes tliirty feet in length, and bear 

 the impress of the bark of the tree in the minutest de- 

 tails. Though I was unable to visit the places where 

 these tree molds occur, I talked with at least half a 

 dozen men who had seen these casts, but none of 



