Xxii MEMOIR. 



ters of the whole group, but its geographical and 

 geological relations, and many other generaliza- 

 tions of much interest and importance. He car- 

 ried the manuscript with him to Europe, intend- 

 ing to have some of the unfinished plates exe- 

 cuted there. This most valuable work was left 

 so nearly complete that it may be regarded 

 as essentially his work. 



His last and his greatest effort in behalf of 

 science was, to carry into effect a purpose, long 

 since formed, of obtaining, through the liberality 

 of the Boston public, a building for the Society 

 of Natural History, which should amply accom- 

 modate its present and prospective collections. 

 In his anniversary Address, in 1846, he set forth 

 in the most lucid and convincing manner, the 

 wants of the Society, the absolute uselessness of 

 adding to its collections in consequence of a 

 want of the means for their preservation and dis- 

 play, and the claims which the objects and labors 

 of the Society had upon the public. By a vote 

 of the Society, this address was afterwards 

 printed and circulated, as an appeal to an en- 

 lightened and liberal public; and it will ever 

 stand as an enduring memorial of his just 

 appreciation of the claims of science, of his 



