12 
THE COMPOUND EYE OF INSECTS AND CKUSTACEA. 
HE anatomy of the insect eye, as described in recent treatises 
and manuals enjoying a wide circulation, is little more than 
a repetition of observations made by Swammerdam,* Murcel de 
SerreSjt Strauss Durkeim,J Diiges,§ and Johann Muller. || For 
the most part, also, the accompanying illustrations consist of 
unaltered copies of figures drawn when microscopic anatomy 
was in its infancy. Consequently, text and illustrations date 
alike from a period when the nature of the terminal elements 
of the optic nerve fibres was entirely unknown, and the histology 
of the several component structures of the eye but very imper- 
fectly understood. 
From the dates given below, and from the recital of the same 
authorities, and the SJime meagre details of the anatomy of the 
compound eye, the reader might naturally conclude that no later 
discoveries had been made, or that no further examinations had 
been attempted. That this is far from being the actual state of 
things, we liope to be able to show in the following pages, 
wljerein the results of certain interesting researches, prosecuted 
by Professor Leydig in Tubingen and by other anatomists, will 
be recorded. Yet it must be admitted that our acquaintance 
with the structure of the insect eye, and with the true character 
• (ler Xntur” and ^‘General History of Insects,” 1GG3 (two cen- 
turies a;ro !). 
t M<?inoire sur les Yeux compos(5s et les Yeux lisses des Insectes.” 1813. 
Montpellier. 
\ “ Conf-iderations "6n(5rales sur I’Anatomie comparde des animaux arti- 
cules, auxfiuelles on a joint I’Anatomie descriptive du Melolontha vulgaris.” 
182H. Paris. 
5 “ ( )b«<*rvalions sur la structure de PG'^il composiS des Insectes.” 1830. 
Annab'.H <1 ch Sciences. 
II “ Zur vergleicbenden I’hysiologie des Gesiebts-Sinnes.” 182G. Also Me- 
moirs publiMhe<l ill “Annales des Sciences,” tom. xvii. and xxii. ; also “ Iland- 
biich der Phyriologie des Menschen.” 1840. Leipsic. “ Zeitschr. f. Physiol.” 
IWi. iv. 1832, &C. &C. 
Br HENRY FRIPP, M.D. 
