REPORT OF THE SECRETARY, 121 



Note (added February 13, 1888). — Tliis last clause above cited is to be uuderstood 

 as includiug the books purchased at tlie expense of the Museum appropriation, but 

 uot uecessarily books obtained by exchange for Museum publications, as it would 

 be difficult, if not impossible, always to discriminate these under our present system. 

 This point is reserved for future consideration, but provisionally it is uuderstood that 

 the librarian is to send books to the Library of Congress if not evidently meant for 

 the Museum. 



S. P. Langley, 



Secretary. 



