GLOSSARY. 



Insectivorous. Subsisting on insects. 



Instinct. The operation of the principle 

 of organized life, independent of all 

 instruction or experience, but by which 

 animals are unerringly directed to do 

 spontaneously whatever is necessary 

 for the preservation of the individual 

 or the continuation of their kind. 



Instinctive. Prompted by instinct; act- 

 ing spontaneously, without reasoning, 

 instruction, or experience. 



Instrumenta Cibaria. The parts of the 

 mouth in insects concerned in the ac- 

 quisition and preparation of the food. 



Intertable. Not perceptible to the touch. 



Integument. A covering which naturally 

 invests the body, as the skin of an ani- 

 mal or the shell of a Crustacean ; or a 

 membrane that invests a particular 

 part. 



Intellect. The understanding ; that facul- 

 ty of the human mind which receives 

 or comprehends the ideas communicat- 

 ed to it by the senses or by perception, 

 or by other means. 



Intellectual. Pertaining to the intellect; 

 perceived by the understanding, not 

 by the senses. 



Intelligence. Understanding; skill. 



Interambulacra. The im perforated plates 

 which occupy the intervals of the per- 

 forated ones, or ambulacra, in the shells 

 of Echinoderma. 



Intercostal. Placed between the ribs ; as, 

 an intercostal muscle, artery, or vein. 



Inter -ganglionic. Belonging to the ner- 

 vous chords in the intervals of the gan- 

 glions, which they connect together. 



Intermaxillary. Situated between the 

 jaws. 



Intermigration. Reciprocal migration. 



IntermuKcular. Between the muscles. 



Internodal. Having a space between one 

 knot or joint and another. 



Interocular. When the antennae of an 

 insect are inserted anywhere between 

 the eyes. 



Interorbital. Situated between the orbits. 



Interosseous. Situated between bones ; 

 as an ijiterosseous ligament or muscle. 



Inter scapular. Situated between the 

 shoulders. 



Intersected. Cut or divided into parts by 

 being crossed. 



Intel-slice. In insects, the space between 

 elevations and depressions running in 

 lines. 



Interstitial. Relating to the intervals be- 

 tween parts. 



Intertropical. Pertaining to those coun- 

 tries which lie between the tropics. 



Interval. An entomological term denot- 

 ing the space between irregular and 

 scattered elevations and depressions. 



Intestinal. Pertaining to the intestines 

 of an animal body ; as, the intestinal 

 tube or canal. 



Introtnit. To enter or to allow to enter ; 

 to be the medium by which a thing en- 

 ters or is admitted. 



Introsusception. The passing of one part 

 of an intestine within another, causing 

 a duplicature of it. 



Intruded. When the head of an insect is 

 nearly withdrawn within the trunk. 



Invertebrate. Destitute of a backbone or 

 vertebral chain. 



Involute. Rolled inwards. Where the 

 exterior lip of a shell is turned inwards 

 at the margin, as in the Cyprsea. 



Iridescent. Having colors like the rain- 

 bow. 



Iris (pi. Irides). The colored circle which 

 surrounds the pupil of the eye, by 

 means of which that opening is en- 

 larged and diminished. 



Irradiated. Made luminous, bright, or 

 shining. 



Irrespirable. Unfit for respiration. 



Irrigate. To water, as land, by causing 

 a stream to flow upon it and spread 

 over it. 



Irrograted. Sprinkled or moistened with 

 atoms, as the earth with dew. 



Isaltel or Isabella-color. A brownish- 

 yellow color, with a shade of dark- 

 red. 



Ischiadic (from ischium, the hip). Per- 

 taining to a rheumatic affection of the 

 hip-joint, generally termed sciatica. 



Islet. In entomology, a spot of a differ- 

 ent color, included in a plaga or 

 macula. 



Isopoda. An order of Crustaceans in 

 which the feet are alike and equal. 



Isolated. Detached from others of a like 

 kind ; standing alone. 



Itinerant. Wandering ; not settled. 



