PSYCHE. 
FRAGMENTS OF THE COARSER ANATOMY OF DIURNAL 
LEPIDOPTERA. 
1. THE LARVA OF DANAIS PLEXIPPUS, OF NORTH AMERICA. 
BY SAMUEL H. SCUDDER, CAMBRIDGE, MASS. 
So very little is known of the points in 
which different lepidoptera agree or dis- 
agree in their internal anatomy, that, 
although very fragmentary, I venture 
to publish the following accounts of dis- 
sections of caterpillars and chrysalids of 
butterflies, made about ten years ago, 
more in the hope of calling attention to 
the need of work of this kind than of di- 
rectly contributing to any general state- 
ments deducible from the observations. 
The literature of the subject is exceed- 
ingly scanty. Swammerdam in_ his 
Biblia naturae (1757) gives illustrations 
and descriptions of the internal anatomy of 
the larva of Aglais urticae ; Herold in his 
Entwickelungsgeschichte der Schmet- 
terlinge (1815) gives admirably full de- 
taiis of the anatomy of both larva and 
pupa of ‘** Pieris brassicae”; Newport 
gives a section on the Development of 
the nervous column of ‘* Vanessa urti- 
cae” in the Philosophical transactions 
for 1854 (repeated in Todd’s encyclo- 
paedia, art. Insecta): and on _ the 
Transformations of the tracheae in the 
same insect in the Philosophical trans- 
actions for 1836 (also repeated as 
above); Brandt also figures the meta- 
morphoses of the nervous system of 
the same species in the Horae societatis 
entomologicae rossicae for 1879, v. 15, 
pl. 14; and in my recent volume on but- 
terflies, quoted below, I have given a 
brief account of the anatomy of larvae 
of butterflies in general and of the 
changes the organs undergo in passing 
through the pupal condition. So far as 
I am aware, these are all the notices 
that have been published of the internal 
anatomy of the earlier stages, and, as 
will be seen, they cover a very narrow 
field, treating, with the exception of my 
little book, of only two species. 
My studies were mostly confined to 
half a dozen insects, which will be sep- 
arately treated, commencing with the 
highest, the account of which will also be 
fullest. 
A good illustration of the general dis- 
position of the organs of the caterpillar 
of Danais plexippus, drawn on a side 
view by Mr. Edward Burgess, will be 
found in my recently published book on 
butterflies,* fig. 78, and this may be 
*Butterflies: their structure, changes and life histo- 
ries, with special reference to American forms. ... 
New York. Henry Holt & Co., 1881.89 
