1868.] SENATE— No. 218. 21 



the hardest. Whenever the opportunity presents itself, I would 

 recommend a careful comparison of the most closely allied 

 species of the same genus, with a view of ascertaining the limits 

 within which fossil species may be determined from the imper- 

 fect materials usually at our command. 



" Finally, I wish you would set aside all such duplicates as 

 are not needed for the use of the Museum, that they may be 

 divided among our correspondents without much loss of time." 



In consequence of these instructions, the whole collection of 

 alcoholic specimens of Mammals and Birds has been overhauled ; 

 the alcohol has been changed where the slightest trace of altera- 

 tion was perceptible. About twelve hundred glass jars have 

 been carefully revised ; also the specimens contained in fifty 

 kegs, containing Mammals, and one hundred and six kegs con- 

 taining Birds ; but the additions to this department have been 

 small since the great accessions derived from the Brazilian 

 Expedition. 



At the same time with this revision of the bulk of specimens, 

 a special investigation of the Insectivora has been commenced, 

 and will be continued during the coming winter. The next 

 work will be a careful overhauling of the collection of skeletons 

 of Mammals and Birds, every part of which is to be marked, 

 so that they may be brought into the lecture room and handled 

 without fear of confusion. 



The whole programme contained in the preceding instructions 

 is to be carried out, as far as the present state of the collection 

 and the scarcity of room will allow. 



