5oo THi: S 1-XSES AND SENSORY ORGANS. 



Lubbock [195] has shown, perhaps, that the range of luminous 

 vibrations visible to insects differs somewhat from that of those 

 discerned by man, and suggests the same with regard to sound 

 vil -rations. It is very possible that such is the case, but this is 

 no evidence that they possess any kind of sensation entirely 

 different from our own. As the proof of any such sensation is 

 impossible, it is useless to discuss it. 



Sporadic Sensory Organs. It is now well known that sensory 

 organs of great complexity occur in the most unexpected posi- 

 tions in many Invertebrates; not only eyes, but auditory organs, 

 even in closely-allied forms, are found in very various parts of 

 the body. For example, amongst the saltatorial Orthoptera, the 

 Acrididae have complex organs of hearing on the first abdominal 

 segment, whilst the Grillidae have similar organs on the anterior 

 tibiae. In the decapod Crustacea ears have been found on the 

 antennules, whilst Mysis has auditory organs in the tail. Graber 

 has found chordotonal organs in various parts of the thorax and 

 abdomen and in their appendages in both larval and perfect 

 insects. In the Diptera, the halteres present characters which 

 have led many to ascribe an auditory function to them, and 

 they are probably correct in this view; lastly, in many Diptera 

 there is a complex organ in the meso-thorax closely connected 

 in its nerve-supply with that of the halteres, which I regard 

 as probably auditory. 



Bibliography : 



196. SERRES, MARCKI, in . ' Mdmoire sur les Yeux compose'e et sur les 

 Yeux lisses des Insectes.' Svo., Montpellier, 1813. Also published in 

 Berlin in (ierman, in 1826. 



197. MULLER, JOHANNES, 'Zur Vergleichenden Physiologic des Gesichts- 

 sinnes des Menschen und der Thiere, nebst einem Versuch, iiber die 

 IJewe^un^fn der Augen und fiber den menschlichen Blick.' 8vo., 

 Leipzig, 1826. 



198. MULLER. JOHANNES, 'Ueber die Augen des Maikiilers.' Archiv. f. 

 Anat. u. I'hysiol. (Meckel's), 1829. 



199. DUGKS, A., ' Observations sur la Structure de l'(Kil compose des 

 Insectes.' Ann. des Sc. Nat., torn. xx.. 1830. 



200. \\'.\<;M K, R., 'Kinige Bemerkungen iiber den Ban der /usanimen- 

 gesetzen Augr-n dor Insecten.' Archiv. f. Natnrge--chichte (\Vie^- 

 niann's), Jahrg. i, IM. i., 1835. 



