1891.1 
359 
[Scudder. 
in which we described these parts in detail to the Society in 1870. 
The classification and detailed description of the organs in the 
different species fell to my share of the work ; the more impor- 
tant general portion and the illustrations were his. 
I think it was this generous work of his for me which continued 
over many years that explains why it was not until eight years 
later that he published any further anatomical papers, for then 
begins a series which continued over another eight years. It 
starts witli a study of the structure of the head and mouth parts 
of the Psocidae and especially of the book-lice, those minute 
pallid objects which one can see only when they move and which 
are fond of the dusty tops of old books in libraries ; they are 
among the most difficult subjects of anatomical study from their 
minute size. He paid special attention to the maxilla on account 
of its strange structure which previous writers had misunder- 
stood ; there occurs between its basal lobe and the tongue a hol- 
low forked chitinous rod, about a third of which projects through 
the lining membrane of the mouth, — a membrane which is elas- 
tic enough to allow it to move backward and forward, and prob- 
ably serves as a sort of pick ; this, which Westwood regarded as 
a process attached to the maxilla, Burgess is more inclined to 
look on as an independent organ. He also discovered glands 
confined within the head region and previously overlooked, 
which lie regards as salivary reservoirs of a very peculiar form. 
His next essay in this direction was an address to the Cam- 
bridge Entomological Club as its President, in which he gave a 
very careful summary of the work that had been done in insect 
anatomy during the preceding two years (1878 and 1879). 
Extending, when printed, over seventeen quarto pages and 
treating of more than sixty different papers, it forms one of the 
very best succinct accounts of this sort ever published, the pith 
of each article being given in a very few words, but enough to 
let the student gain a fair notion of its contents. 
But the most important and valuable of his papers was that 
published in our Anniversary Memoirs in 1880, giving a detailed 
account of the anatomy of one of our commonest insects, the 
milkweed butterfly, and the abstract of a part of it published a 
little earlier in the American Naturalist, in which the structure 
and action of a butterfly’s trunk were carefully explained. The 
general structure of this organ had long been known, but not in 
