August 5, 1904.] 



SCIENCE. 



185 



During the summer of 1903 the writer col- 

 lected fossils in the Niobrara shales in South 

 Dakota, finding the remains of many plesio- 

 saurs. In nearly every instance a large num- 

 ber of siliceous stones were found associated 

 with the bones, often embedded in the matrix 

 en masse. In one specimen in which the 

 largest dorsal vertebrse were four inches in 

 diameter, there was at least half a bushel of 

 these stomach stones, ranging from the size 

 of a walnut to four inches across. 



Considering the weight of these stones, the 

 wonder is that so many specimens contain 

 them. One would expect that when the flesh 

 began to decompose, the weight of these stones 

 would be too great to be contained by the 

 weakened tissues and that they would be lost 

 before the animal reached its final resting 

 place. This may well explain the absence of 

 stones in some cases. 



Throughout the Niobrara formation in 

 Dakota baculites are very abundant while 

 scaphites are rare, especially in the shales. 

 I could not be certain that any of the baculites 

 associated with the plesiosaur remains had 

 been eaten by these animals but in plesiosaur 

 specimen number 5803 of the American Mu- 

 seum collection I found a variety of fossils 

 representing this animal's last meal. Great 

 numbers of fish vertebrae were scattered 

 among the bones, while there were several 

 pterodactyl bones, broken in small sections. 

 But of chief interest were seven scaphites, 

 more or less broken, which had without ques- 

 tion been eaten by this animal. One other 

 specimen had scaphites associated with it. 

 The conclusion seems evident that invertebrate 

 animals formed a large part of the food of 

 plesiosaurs and that, in default of crushing 

 teeth, the breaking up of the food was effected 

 by the aid of these stomach stones, the presence 

 of which further implies a thick-walled, giz- 

 zard-like arrangement in the alimentary canal. 



Barnuii[ Brown. 



THE ALPINE LABORATORY OF THE BOTAN- 

 ICAL SEMINAR OF THE UNIVERSITY 

 OF NEBRASKA. 



The striking diversity of conditions and of 

 vegetation in high mountain ranges makes 



them ideal places for field experiment. Their 

 value is greatly increased, moreover, when 

 their slopes arise directly from the plain, as in 

 frontal ranges. This is the case at Pikes 

 Peak in the Eampart range of the Rocky 

 Mountains, where the distance from the plains 

 at an altitude of 1,800 meters to the alpine 

 summit at 4,200 meters is less than ten miles. 

 The significance of this is evident when one 

 reflects that these ten miles contain in minia- 

 ture the habitats and formations found be- 

 tween latitude 40° and the arctic circle : in 

 less than a half-day, one may pass from the 

 temperate zone through the boreal-subalpine 

 to the arctic-alpine zone. The opportunity 

 for the study of the development and struc- 

 ture of vegetation is unique. The major 

 zones are in evidence as nowhere else, and 

 their ecotones are clear-cut. Weathering and 

 erosion are at a maximum, making new 

 habitats and destroying old ones, and the de- 

 velopmental history of formations may be 

 read from hundreds of stages. Experimental 

 methods in vegetation and in the evolution of 

 new forms may be applied with an ease and 

 a certainty of freedom from accidents and in- 

 terference which can be obtained only with 

 dilficulty in other regions. The dream of the 

 physiologist (ecologist) to have his laboratory 

 out-of-doors may be realized here, and it is 

 merely a matter of time until methods will 

 be found by which research will deal primarily 

 with the experiments of nature, and the walled 

 laboratory will be relegated to a purely sec- 

 ondary place. 



The reconnoissance work done by different 

 members of the botanical seminar of the Uni- 

 versity of Nebraska in various parts of the 

 Rocky Mountains from 1893 to 1898 showed 

 that the Pikes Peak region possesses the com- 

 bined advantages of accessibility and diversity 

 to a degree found nowhere else. This country 

 was worked over more in detail in the summer 

 of 1899, and Minnehaha, at an altitude of 

 2,500 m. on the Cog railway, was selected as 

 a base. Minnehaha is within an hour's walk 

 of the plains, and an easy climb of two hours 

 brings one to timber line on Mount Baldy. 

 It is in the midst of the coniferous and aspen 

 forests of the subalpine zone, in a locality 



