ASA GRAY. 751 



-rohn Frtiser, of the last century, aud John Lyon, Michaux the younger, 

 Pursh, Nuttall, Curtis, and others, of this, mentioning their discoveries, 

 with critical remarks on the species they observed aud on their distri- 

 bution ; aud then he describes his owu journey, adding notes on the 

 plants met with by the way and in the mountains, commencing his ob- 

 servations at Barper's Ferry. His journey among the North Carolina 

 mountains included the ascent of the " Grandfather," 5,897 feet in eleva- 

 tion, and the Roan Mountain, G,30G feet. This is one among a number 

 of such excursions. 



Another labor of this period was the revision of his "Elements of 

 Botany," which, without much change of general method, he made a 

 far more comprehensive aud thorough treatise, and in 1842 issued under 

 the title of the "Botanical Text book." Since then successive editions 

 have appeared with large advances, as the science required. By the 

 firth edition, that of 1879, the subject had so expanded that it was di- 

 vided, and the work made to include only Structural Botany, covering 

 Morphology, Taxonomy and Phytography, leaving Physiological and 

 Cryptogamic botany' to other hands. The second volume, an exposition 

 of Physiological Botany, appeared in 1885 from the pen of his colleague, 

 Prof. G. L. Goodale. A third volume on Cryptogamic Botany is prom- 

 ised by another colleague, Prof. W. G. Farlow. 



Gray never entered on duty at the Michigan University, it being im- 

 possible for him to carry on his publications so far away from the New 

 York herbaria aud botanical libraries. In 1842 he was invited by the 

 Fellows of Harvard College to the Fisher Professorship of Natural 

 History, recently founded on a bequest by Dr. Joshua Fisher. The 

 duties of the professorship included the delivery of a course of lectures 

 on botany, aud the direction of a small botanic garden which had been 

 established in Cambridge in 1805, under the auspices and with the 

 assistance of the Massachusetts Society for promoting Agriculture. 

 Thomas Nuttall had charge of the garden from 1822 to 1828, and after 

 that it was without a head until the appointment of Dr. Gray. The 

 garden was still poor in funds, and had not even a herbarium to aid 

 Gray iu his botanical studies. But he entered on the duties with zeal, 

 conducted the required lectures in the most lucid and attractive man- 

 ner, freely gave the use of his study to such students as wished to learn 

 more of the science than they could acquire from the lectures, and 

 gathered a vast herbarium. And all the time he carried on an enor- 

 mous correspondence with promptness, aud answered all social demands 

 with unfailing courtesy, besides continuing his botanical investigations 

 and writing books and memoirs. These duties continued until 1872, 

 when he was relieved from that of teaching and the charge of the 

 garden. In 1864 he made the offer to Harvard College of the herbarium 

 and library which he had gathered, already very large, on conditio. i of 

 their erecting a fire-proof building to contain them, which was accepted. 



