^V AND ^^^^ 



JOURNAL OF VARIATION. 



No. 3. Vol. Y. March 15th, 1894. 



1'lie Life-plistory of a Lepidopterous Insect;, 



Comprising some account of its Morphology and Physiology. 

 By J. W. TUTT, F.E.S. 



Chap. I. 



CLASSIFICATION. 



1. On the position of the Insecta in relation to allied 

 Classes. — The Sub-Kingdom Annulosa (annulus : a ring) is charac- 

 terised essentially by the fact that the bodies of the animals belonging 

 to the several classes of which it is composed are made uj) of rings or 

 segments arranged along a longitudinal axis. It is usually divided into 

 seven Classes, of which Insecta is one. Five of these Classes are 

 grouped together to form the Section Arthropoda, and the classification 

 of this section may be tabulated as follows : — 



AETHROPODA. — Animals having a body composed of segments 

 and jointed ; segmental apj^endages articulated to the body. 

 Division I. — Branchiata. — Breathing by means of branchias or gills. 



Class 1. — Crustacea. — Head and thorax united into a cephalo- 

 thorax ; abdomen distinct ; two pairs of antennae — called 

 respectively antennaa and antennules. 

 Division II. — Tracheata. — Breathing by means of tracheee. 

 Sub-division 1 : — Chelicerata. — No true antennee. 



Class 2. — Arachnida. — No distinct head, the head and thorax 

 being united to form the cephalo-thorax ; body divided 

 generally into cephalo-thorax and abdomen ; four pairs of 

 thoracic legs ; no abdominal legs. 

 Sub-division 2 : — Antennata. — With one pair of antennfe. 



Class 3. — Onychopora (Prototracheata). — Body not divided into 



distinct regions ; legs numerous, but variable in number. 



Class 4. — Mijriapoda. — Head distinct; little or no distinction 



between thorax and abdomen ; legs very numerous. 

 Class 5. — Insecta {Kexapoda). — Body divided into head, thorax 

 and abdomen ; six legs (attached to thoracic segments) ; 

 usually two pairs of wings. 

 In a very recent paper " On the nervous system and sense organs of 



