280 CLASS VILI. 
the eyes are large air-sacs or wide air-tubes, from which fine 
branches arise, which in part run to the pigment and connect its 
granules, in part pass into blind cylindrical tubes situated between 
the nerve-threads of the vitreous cones’. 
De tA Hire, who first discovered the simple eyes of Insects, 
thought he might conclude from their presence, that the larger 
(compound) eyes were not organs of vision. That they also serve 
for vision the experiments of SWAMMERDAM, who smeared them in 
flies with black varnish, have proved. ReAuMuR also did the 
same with bees. It is more difficult to determine exactly in what 
respects the office of the compound and simple eyes differs, although 
the last probably serve principally for seemg near objects. The 
bees, in which ReAuMuR had smeared these eyes with a dark 
varnish, whilst their compound eyes remained uncovered, could not 
find their hives’; moreover all flying Insects are invariably pro- 
vided with compound eyes. There are Insects which have simple 
eyes alone, as the Myriapoda and Parasitica (also the larve of the 
Lepidoptera) ; few Insects are entirely without eyes, like a parasitic 
Insect of bees (Braula Nirzscu$), and a new genus of the Carabict, 
Anophthalmus of Scumipt‘, and different Myrtapoda. In the 
diurnal butterflies and most Coleoptera, there are two compound 
eyes alone, without simple eyes; simple eyes are also wanting in 
certain Diptera, in Forficula, Blatta and other Orthoptera, in many 
Hemiptera ; where they occur in company with compound eyes, 
usually three are present, sometimes, as in Castnia, Sesia, Noctua, 
Gryllotalpa, two’. 
1 See on the compound eyes of insects amongst others Hooxr, Micrographia, 
Londini, 1667, Tab. 24, SwAMMERDAM, Bibl. nat. pp. 487—498, Tab. xx., J. MUELLER, 
Zur vergl. Physiol. des Gesichtsinnes, Leipzig, 1826, 8vo. s. 307—390 ; by the same, 
Fortgesetzte anatomische Untersuchungen ueber den Bau der Augen bei den Insecten u. 
Crustaceen, in MrcKn’s Archiv, 1829, s. 38—64, and Ueber die Augen des Maikifers, 
ibid. s.177—181 ; F. Wit, Beitriige zur Anat. der zusammengesetzten Augen, Leipzig, 
1840, 4to; A. BRAN'TS on the air-tubes in the compound eyes of the Articulata, Tyjd- 
schrifi voor nat. Gesch. en Physiol. X11. 1845. 
2 Mem. p. servir a U Hist. des Ins. v. pp. 287—289. 
3 GurMaR, Magazin der Entomol. 111. 1818, s. 314. 
4 See Jac. Srurm, Deutschland’s Insecten Xv. 1824, pp. 129—137, Taf. 303. Also 
a genus of the Xylophagi, Anommatus terricola, RoBERT, Acad. roy. de Brucelles, 1836. 
> Kuue, Ueber das Verhalten der einfache Stirn und Scheitelaugen bei den Insecten 
mit zusammenges Augen. Physikal-Abhandlungen der Kénigl. Akad. der Wissensch. 2u 
Berlin, aus den Jahre 1831, 8. 301—312. 
