346 THE POPULAR SCIENCE MONTHLY 



Yaqui Indians in the interior, he crossed the Gulf of California to the 

 peninsula of Lower California and went thence by sea to San Fran- 

 cisco. Among the plants collected in northern Sonora and along the 

 shores of the Yaqui Kiver, many proved to be species hitherto unknown. 

 One of them, a columnar cactus, had fruit densely covered with spines, 

 which was used by the Indians for brushing their hair. This was 

 named Cereus pecten-aboriginum by Engelmann, and afterwards de- 

 scribed by Sereno Watson in Volume 21 of the Proceedings of the 

 American Academy. 



Dr. Palmer next went to Utah. He carried with him a letter of 

 introduction to Brigham Young, who assisted him most willingly in his 

 work by giving him letters to the authorities in the southern part of the 

 territory. His work was chiefly in the vicinity of St. George, in the 

 southwest corner of the territory. This region, considerably lower than 

 the great Utah basin, is remarkable for its semitropical products, such 

 as pomegranates, cotton, etc., on which account it is sometimes called 

 Dixie Land. From St. George he made a long and painful journey 

 across what is now the southern corner of Nevada to Hardyville and 

 Camp Mohave, on the Colorado Elver, and thence across southern 

 California to San Francisco. 



On his return to Washington, in November, 1870, he received a 

 letter from Dr. Torrey, congratulating him on the successful accom- 

 plishment of his mission. " I had anticipated much pleasure," Dr. 

 Torrey wrote, " in spending several days with you at the agricultural 

 department, and in hearing from you an account of your doings and 

 adventures. 



" You have, in the last few years, done great service to North Amer- 

 ican botany, and I trust that we shall receive yet greater benefit from 

 your explorations. There are many choice plants to be found in our 

 little-explored states and territories. 



" I should be delighted to look over your late discoveries, and I 

 hope you will be able to spare me duplicates. It is of great importance 

 that the herbarium of Columbia College should be as complete as pos- 

 sible in North American plants." 



The commissioner of agriculture, Horace Capron, in his report for 

 1870, calls special attention to the collections of Dr. Palmer and states 

 that the botanical material accumulated by him "is now in process of 

 elaboration by the distinguished American botanists, Drs. Gray, Torrey 

 and Engelmann, and includes a considerable number of plants new to- 

 science which will be greatly prized by scientific botanists, and eagerly 

 sought by botanical institutions at home and abroad." 



" The design of establishing at the seat of government a collection 

 of plants worthy of the name of a national herbarium is thus in process 

 of rapid accomplishment, at a comparatively small cost; and it is confi- 



