BOSTON SOCIETY OF NATURAL HISTORY. 191 



study of the geological distribution of animals and plants ; especially to the latter, as 

 affected by, or as evidence of, the operations, movements and diffusion of the races of man. 

 To the collections and investigations of Dr. Pickering and Professor Dana, the scientific 

 fame of the expedition is principally due. 



In October, 1843, Dr. Pickering again went abroad, visiting during his tour Egypt, 

 Arabia, India, and .eastern Africa, more particularly for the purpose of verifying obser- 

 vations made while with the Exploring Expedition. On his return he settled in Boston, 

 and occupied himself in preparing his " Races of Man and their Geographical Distribu- 

 tion," published in 1848, being Volume XT, of the Exploring Expedition. In 1850, 

 appeared in the " Edinburgh New Philosophical Journal," his " Enumeration of the Races 

 of Man." 



In 1854, his work " The Geographical Distribution of Animals and Plants," was pub- 

 lished. This work constituted Volume XV of the Exploring Expedition. 



The proceedings of the American Academy of Arts and Sciences, contain the following 

 articles by Dr. Pickering : Observations on the Egyptian Computation of Time, appearing 

 in October, 1849; on the Egyptian Astronomical Cycle, in May, 1850 ; on Sulphur Vapor, 

 in December, 1856 ; on the Coptic Alphabet, in March, 1859 ; on the Geographical Distri- 

 bution of Species, in March 1859, and December 1800 ; and on the Jewish Calendar, in 

 October, 1864. 



In June, 1867, he prepared a paper " On the Gliddon Mummy case in the Museum of 

 the Smithsonian Institution," published in Volume XVI of the Smithsonian Contributions 

 to Knowledge. 



In 1876, was published at Salem the " Geographical Distribution of Animals and Plants ; 

 Part II ; Plants in their Wild State." 



The great work of his life was " The Chronological History of Plants." This truly 

 remarkable production, to which he had devoted sixteen years of indomitable industry 

 and laborious research, was going through the press at his own expense at the time of 

 his death. While the form in which it is cast will prevent its use as a book for popular 

 study, to the thorough student and teacher it must ever be unequalled as an exhaust- 

 ive authority on the subjects of which it treats. 



Dr. Pickering was elected a member of the Boston Society of Natural History, March 

 3d, 1858. As a member, his attendance upon meetings was constant, and his communica- 

 tions, whether elaborately written out, or merely remarks upon the subject at the time 

 before the Society, were always indicative of thorough knowledge and acquaintance with 

 the matter. The range of his general information was very extensive, and whether he 

 was speaking of Feejean pottery, or rare botanical forms found in the mountains of New 

 England ; of the character of the alluvial deposits of South American rivers, or the origin 

 of the Esquimaux ; whatever he might have to say was interesting and instructive in a 

 high degree. Most of the present members of the Society will recall his controversy 

 with the late Dr. Thomas M. Brewer, relative to the introduction of the European spar- 

 row, in which Dr. Pickering took very strong ground adversely to the naturalization of 

 the bird, quoting a formidable array of authorities in support of his position, and predic- 

 ting very undesirable results in case the proposed experiment should be attempted and 

 prove successful as to the ability of the sparrow to exist in this climate. 



