Scudder.J 
360 
[Dec. 16, 
the detail which his dissections brought to view, while the ancil- 
lary organs within the head by which only the precise action of 
the uncoiled tongue could be explained were first made known 
by him ; though had his first paper been delayed but a few 
months, the credit would have to be given to a German investi- 
gator, whose work was neither so thorough nor so nice. Burgess 
showed in these papers, and delineated with great skill, a 
pharyngeal sack at the base of the tongue amply provided with 
muscular fibers running in such a variety of directions that their 
united action would greatly diminish the space in the interior ; 
and furnished likewise with diverging bands of muscles which 
when brought into play would as greatly and as certainly enlarge 
the sack. By the alternate action of these sets of muscles and 
the intermittent opening and closing of the sack a pumping ac- 
tion would ensue, were there any valve present permitting the 
flow of the fluids entering through the tongue canal and prevent- 
ing their return. This he discovered in a triangular muscular- 
flap or epipharynx at the upper base of the tongue or the anterior 
extremity of the pharyngeal sack, and the structure of the parts 
proves so simple that its action is unquestionable. In his own 
words it is as follows : “The trunk is unrolled and inserted in 
the nectary of a flower ; at this moment the muscles which sus- 
pend the oral sack contract, and the mouth cavity is thus ex- 
tended, creating a vacuum which must be supplied by a flow of 
honey through the trunk into the mouth. When the mouth is 
full, the muscular sack contracts, the oral valve closes the aper- 
ture to the trunk, and the honey is forced backward into the 
oesophagus. The mouth cavity is then again opened and the 
same process repeated. In the muscular mouth sack we have 
thus a pumping organ, of action too simple to be misunder- 
stood.” 
In the text and plates accompanying the larger memoir, he 
gave a more precise and detailed account of both the external 
and internal anatomy of the insect discussed than had ever been 
given before of the anatomy of any perfect butterfly, and brought 
to light a number of interesting points that had been nearly or 
quite overlooked before, such as the nature of the striae on the 
scales, the musculature of the tongue and its intimate structure, 
the cuticular processes of the food reservoir, the backward 
course and chaigbered enlargement of the aorta within the 
