10 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



suddenly in an arid desert-like region, where cacti and acacias are the con- 

 spicuous plants. 



So inadequately known is the flora of Colombia that even along the regular 

 routes of travel many species are found that are either new, unrepresented in 

 American herbaria, or known only from specimens preserved in European 

 collections. 



The botanical collection resulting from this expedition is one of 

 the largest and most important ever obtained in Colombia. 



EXPLORATION OF THE PALEOLITHIC REGIONS OF FRANCE AND SPAIN 



During September, 1922, Mr. M. W. Stirling, of the National 

 Museum, explored the paleolithic regions of southern France and 

 northern Spain. Besides visiting all of the important sites where 

 remains of ancient man have been discovered, the expedition entered 

 a great many caves previously unknown to science. Regarding the 

 great promise of the region for archeological work, Mr. Stirling 

 reports as follows: 



The idea has become prevalent in America that this region has been practi- 

 cally exhausted archeologically. Although the previous existence of paleo- 

 lithic man in this locality has been known for half a century, it may be truly 

 said that the work of exploration has hardly begun. 



The habitations of the Stone Age are closely linked with the limestone forma- 

 tion which overlies large areas in this part of Europe. These may be said to 

 fall into two classes, i. e., rock shelters and caverns. The former are under- 

 cuts in the limestone made by the rivers in the early Pleistocene or late Plio- 

 cene. A general elevation of the land has caused the streams to*deepen their 

 channels, thus leaving the undercuts well above the surface of the water. 

 These were utilized as dwelling places by paleolithic man and in many instances 

 were artificially modified. There are literally miles of relic-bearing deposits 

 of this class that have not yet been touched. The possibilities in this field are 

 very great. 



The caverns of the Dordogne region are for the most part comparatively 

 small, while those in the department of Arriege are immense caves of a most 

 spectacular nature. Of the former class are the grottoes of Font du Gaume, 

 Combarelles, La Mouthe, Marsoulas, Montesquieu, and others. Of the latter 

 class are the immense caves in the neighborhood of Foix, as for example, Salig- 

 nac, Ussat, and Niaux. The tunnel of Mas d'Azil is the remnant of such a cave. 



Many of these caverns have become blocked with sediment owing to the fact 

 that they frequently slope downward from the entrance. Messrs. Stirling and 

 Patton entered at least a dozen such caves which had become sealed at varying 

 distances from their mouths. The opening of such caves has heretofore been 

 left entirely to chance. Scientific endeavor at this work should produce most 

 fruitful results. The sealing of these caves has been a fortunate accident of 

 nature, since the contents are by this means preserved intact. 



Of the regions visited, that in the neighborhood of Altamira, in Spain, and 

 Ussat, in France, give most promise of rich returns to the archeologist. 



CENTENARY OF THE BIRTH OF SPENCER FULLERTON BAIRD 



A meeting was held in the auditorium of the National Museum 

 on the evening of February 3, 1923, to celebrate the centenary of the 



