VI PREFACE. 
pect of a visit to Brazil, as a mere vacation it had little 
charm for me. Single-handed, I could make slight use 
of the opportunities I should have ; and though the ex- 
cursion might be a pleasant one for myself, it would 
have no important result for science. I could not forget 
that, had I only the necessary means, I might make col- 
lections on this journey which, whenever our building 
could be so enlarged as to give room for their exhi- 
bition, would place the Museum in Cambridge on a level 
with the first institutions of the kind. But for this a 
working force would be needed, and I saw no possibil- 
ity of providing for such an undertaking. While I was 
brooding over these thoughts I chanced to meet Mr. Na- 
thaniel Thayer, whom I have ever found a generous friend 
to science. The idea of appealing to him for a scheme 
of this magnitude had not, however, occurred to me ; 
but he introduced the subject, and, after expressing his 
interest in my proposed journey, added, " You wish, of 
course, to give it a scientific character ; take six assist- 
ants with you, and I will be responsible for all their 
expenses, personal and scientific." It was so simply said, 
and seemed to me so great a boon, that at first I hardly 
believed I had heard him rightly. In the end, I had 
cause to see in how large and liberal a sense he proffered 
his support to the expedition, which, as is usual in such 
cases, proved longer and more costly than was at fir^t 
anticipated. Not only did he provide most liberally for 
assistants, but, until the last specimen was stored in the 
Museum, he continued to advance whatever sums were 
