SKETCH OF PROF. GRAY. 493 



meaning from that expressed by the same term when the work was 

 commenced. The annexation of Texas, the acquisition of California and 

 other territory by the Mexican War and, later, the Gadsden Purchase, 

 changed not only our geographical but our phytographical boundaries. 

 Individual and government explorations were pushed not only into 

 the newly-acquired Territories, but our older possessions were more 

 thoroughly examined, and materials came in at such a rate that to con- 

 tinue the Flora as then commenced would require an appendix larger 

 than itself. Each of its authors then occupied himself with studying 

 the new materials as they came to hand, and in giving their results to 

 the scientific world. This interruption of the Flora was followed by 

 the publication, by both Dr. Gray and Dr. Torrey, of a series of most 

 valuable botanical memoirs, sometimes conjointly, but oftener sepa- 

 rately. These may be found in the various Government Reports, and 

 in the transactions of the American Academy of Arts and Sciences, of 

 the Smithsonian Institution, and other learned bodies. 



The most conspicuous of these contributions to our North Ameri- 

 can Botany by Dr. Gray are, " Plantoe Lindheimeriance" giving an ac- 

 count of the plants collected in "Western Texas, by F. Lindheimer ; in this 

 memoir he was aided by Dr. George Engelmann ; " Plantce Fendleri- 

 ance Nbvi-Mexicance" a description of the plants collected in New Mex- 

 ico, by Aug. Fendler ; " Plantoe Wrightiance Texano-Neo-Mexicanai" 

 describing the extensive collections of Charles "Wright, A. M. This 

 paper is in two parts, and illustrated. Another memoir, " Plantoe, Nbvce 

 Thurberiance" though shorter than those already named, is important 

 as describing an unusual number of new genera and species. These 

 contributions are not confined to the working up of the materials of 

 the particular collections of which they treat, but in many cases whole 

 genera are elucidated and rearranged in a masterly manner. 



These memoirs are mentioned out of their chronological sequence, 

 as they may be considered, as well as those published by Dr. Torrey, 

 as material accumulated for the use of whoever may undertake that 

 Flora of North America for which botanists are hopefully looking. 



In 1848 appeared the first volume of " Genera Floral America} 

 Boreali - Orientalis Illustrata" or, as it is best known, under its shorter 

 title, " Gray's Genera." The object of this work was to give a typical 

 specimen of one or more species of each genus of North American 

 plants, with accurate analyses. The drawings for this work were made 

 by Isaac Sprague, and for accuracy of detail and neatness of execution 

 have not been excelled. Two volumes, containing one hundred plates 

 each, were published, when, to the regret of all American botanists, the 

 publication was suspended for the same reasons that we have given for 

 the discontinuance of the " Flora." 



The most voluminous and in some respects the most important of 

 Dr. Gray's contributions to science relate to extra-American botany ; 

 we refer to the " Botany of the United States Exploring Expedition." 



