1891.] 
361 
[Scudder. 
thorax, and the false claspers of the male abdomen, a remarkable 
series of new observations to have been made upon a single 
insect. 
His discovery of the strange course of the aorta in this butterfly 
led him to pursue the subject further by the dissection of a vari- 
ety of lepidopterous insects, and to embody his results in a brief 
illustrated paper in our Proceedings the following year, by which 
he showed that if we except the peculiar course of the anterior 
branch [of the aorta] in the hawk-moth, we have [in the Lepi- 
doptera] a gradual series from the butterflies downward. In the 
former a distinct horizontal aortal chamber is present; in the 
higher moths a vertical node replaces the chamber, and this 
vanishes in the lower moths.” 
In another paper in our Proceedings for the same year, he 
described and figured the mouth parts of the water-tiger or larva 
of Dytiscus, whose means of taking food had before that been so 
much of a puzzle that the insect had been described as entirely 
lacking a mouth ; and, indeed, the ordinary aperture does appear 
to end in a perfectly closed seam, but by transverse sections 
Burgess was able to show that the upper and lower chitinous 
plates at this point are closely interlocked so as merely to allow 
the passage of a thin stream of fluid when its grip is loosened by 
muscular action of the parts around it, while behind it a muscu- 
lar pharyngeal sack pumps the fluids into the oesophagus much as 
in the butterflies ; only here the mandibles serve as the canals to 
bring the fluid to the mouth cavity, each being pierced by a canal 
the proximal ends of which lie opposite the mouth cavity when 
the mandible tips are brought together, as they would be when 
plunged into the body of a victim. The water-tiger, therefore, 
“ far from being mouthless as ordinarily assumed, has in fact a 
very wide mouth, though its lips are closely locked together by 
a dove-tailed grooved joint, developed for this purpose.” 
Two other anatomical papers were prepared at the request of 
the U. S. Entomological Commission upon the grasshopper Ana- 
brus and the moth Aletia, the latter in conjunction with Dr. 
Minot. Though full of important details, they furnish nothing 
so novel and interesting either technically or generally as to make 
it desirable to dwell upon them here ; it may only be mentioned 
that they show the care, patience, and skill with which all his 
anatomical work was done. 
