284 



THE POPULAR SCIENCE MONTHLY. 



its trough has been filled up by glacial de- 

 tritus and alluvium. It thereby approximates 

 in appearance to a plain. This appearance 

 is due to the inability of the central stream 

 to scour for itself a central channel a fact 

 attributable to the width of the valleys and 

 the consequent absence of glaciers on any 

 scale, and to the short summers, which do 

 not last long enough, or receive sufficient 

 solar heat, to admit of a very powerful erosive 

 impetus being communicated to the melting 

 snows. Mr. Curzon estimates the extreme 

 length and breadth of the Pamirs to be 

 nearly equal, and each about one hundred 

 and fifty miles. 



A Model Public Library. The report of 

 the Board of Directors of the Los Angeles 

 Public Library, Cal., furnishes many facts of 

 much interest. One of the most noteworthy 

 of them is the declaration that the library 

 has been a paying investment for the city, as 

 a means of education and recreation to the 

 citizens, and as an attraction to the tourist 

 population. Among the novel features is 

 that of the circulation of current literature, 

 which has met with hearty appreciation 

 from the beginning, and is believed to have 

 been a potent feature in encouraging the 

 reading of the best class of the books and 

 periodicals of the time. Another popular fea- 

 ture is the musical department, which has 

 been much utilized by students of music, and 

 has proved a means of education. Early in 

 the administration of the library, civil-service 

 rules were adopted for the appointment and 

 regulation of the staff of attendants. The 

 first appointments were made after a rigorous 

 examination into the qualifications of appli- 

 cants, ignoring all objects except the greatest 

 good of the library. A training class was es- 

 tablished in November, 1891, from the gradu- 

 ates of which, and of succeeding classes, all 

 appointments to the staff have since been 

 made. Appointments and promotions are all 

 regulated according to efficiency and length 

 of service; and it being understood that 

 the employed of the library are entitled to 

 retain their positions during good behavior, 

 the formality of reappointment from year to 

 year has not been recognized as necessary 

 or advisable. It shows how little the Ameri- 

 can people are removed from barbarism in 

 the management of public affairs that these 



matters embodying the plainest and most 

 obvious common-sense principles have to be 

 explained in the report and shown to be right. 

 The library has 42,313 volumes; gave out 

 for reading at home or in the library or the 

 reference room, 489,086 volumes in 1894; 

 has 18,057 registered members ; and employs 

 nineteen attendants. 



The Office of Natural Selection. Xatural 

 selection, Prof. A. S. Packard holds, in his 

 paper on the Inheritance of Acquired Char- 

 acters, as he has from the first insisted, is 

 not an initial or impelling cause in the origi- 

 nation of new species and genera. It does 

 not start the ball in motion ; it only, as we 

 might say, guides its motions down this or 

 that incline. It is the expression, like that 

 of " survival of the fittest " of Herbert Spen- 

 cer, of the results of the combined operation 

 of the more fundamental factors. In certain 

 cases we can not see any room for its action ; 

 in some others we can not at present explain 

 the origin of species in any other way. Its 

 action increased in proportion as the world 

 became more and more crowded with diverse 

 forms, and when the struggle for existence 

 had become more interesting and intense. 

 It certainly can not account for the origi- 

 nation of the different branches, classes, or 

 orders of organized beings. It in the main 

 simply corresponds to artificial selection ; in 

 the latter case man selects forms already 

 produced by domestication, the latter afford- 

 ing species and varieties due to change in 

 the surroundings that is, of soil, climate, 

 food, and other physical features, as well as 

 education. 



An Ancient Flint-Implement Factory. 



Large numbers of flaked stone implements 

 of beautiful form and material, and in some 

 cases of unusual size, are abundant in the 

 Mississippi Valley within a radius of one 

 hundred and fifty miles of St. Louis. An 

 important site, from w r hich a material and 

 instruments were supplied closely correspond- 

 ing with those used in the St. Louis region, 

 has been found nearly three hundred miles 

 southwest of that city, and is described by 

 Mr. W. H. Holmes. The stone is a whitish 

 or light-gray chert, of conchoidal fracture, 

 flaking easily, and resonant. The excava- 

 tions are in three groups, occupying four or 



