USED IN NATURAL HISTORY. 



85 



which lies between two or more 

 veins. 



INTE'XINE. That coating of the 

 pollen-grain which is situated 

 next to the extine, constituting a 

 fourth layer of the pollen-grain 

 in certain plants. 



IX'TINE. The inner coat of the shell 

 of the pollen-grain in plants. 



ISTOR'TA. Lat. Twisted inwards. 



INTO'RTIOX. The turning or twist- 

 ing of a shell, in any particular 

 direction. 



INTRAMA'RGINAL. Within the mar- 

 gin. 



IJTTRO'RSE. Turned inwards. 



INTRU'SION. The act of thrusting or 

 forcing in. 



INTUSSUSCE'PTIOX. fr. lat. intus, 



within ; suscipio, I receive. The 

 mode of increase peculiar to or- 

 ganized bodies. 



Ijfu'us. One of the names of Pan, 

 the heathen god of shepherds, 

 and of flocks. The Barbary ape 

 has received this name. 



IJTVAGIWA'TIOX. fr. lat. in, in; va- 

 gina, a sheath. Intussusception. A 

 sheathing of one part within an- 

 other. 



INVERTEBRA'TA. fr. lat. in, with- 

 out; vertebra, a bone or joint of 

 the spine or back-bone. A divi- 

 sion of. the animal kingdom, em- 

 bracing mollusks, insects, and 

 other animals which have no ver- 

 tebrae, or internal bony skeleton. 



INVER'TEBRATE. Without vertebrae; 

 wanting the spinal column. 



INVERSE. Inverted. 



IWVOLU'CELS. The partial involu- 

 cra of umbelliferous plants. 



IWVOLU'CRATED. Covered with an 

 involucre. 



IKTVOLU'CRE. An accessory envelope 

 of a flower, formed of bracts. A 

 covering. 



INVOLU'CRUM. Lat. Involucre. 



IN'VOLUTE. Having the exterior lip 

 turned inwards at the margin. 



INVOLUTION. That part which in- 



volves or inwraps another. 



3D 



IRI'DE.B. A family of plants 01' 

 which the Iris is the type. 



TRIBES. Lat. plur. of Iris. 



IRIDIS'CENT. fr. lat. iris, a rainbow. 

 The property of shining with 

 many colours, like a rainbow. 



I'RIS. That part of the eye in 

 which die pupil is situate; a ver- 

 tical partition between the ante- 

 rior and, posterior chambers of the 

 eye. 



IRIS'ATED. Applied to any mineral 

 which exhibits the prismatic co- 

 lours, either externally or inter- 

 nally. 



IRREGULAR BIVALVES. Those bi- 

 valves which are not uniform in 

 shape throughout the species. 



IRREGULAR COROLLA. Having its 

 upper and lower sides unlike. 



IRRITABI'LITT. fr. lat. irrito, I pro- 

 voke. A power, possessed by all 

 living organized bodies, of being 

 acted upon by certain stimulants, 

 and of moving responsive to, or 

 consequently to such stimulation. 

 It is the ultimate vital property. 



IR'RITANS. Lat. Irritating. 



ISCHI A'Tic.-fr. gr. ischion, the haunch. 

 Belonging or relating to the 

 haunch. 



IS'CHIUM. The hip-bone; the seat- 

 bone. 



ISLA'NDICUS Lat. Belonging or re- 

 lating to Iceland. 



Iso. fr. gr. isos, equal. A prefix 

 denoting equality or similarity. 



ISO'BRTOUS. fr. gr. bruo, to grow. 

 Growing equally. 



ISO'CARDIA. fr. gr. isos, like ; kardia, 

 heart. Name of a genus of cha- 

 ma'cea. (p. 82, Book v). 



ISO'CARDIA. Lat. plur. of Isocardia. 



ISOCHIM'ENAL. fr. gr. isos, equal; 

 cheima, winter. Isochimenal lines 

 pass through all places where the 

 mean winter temperature is the 

 same. 



ISOCLI'NIC LINES. fr. gr. klino, to in- 

 cline. Lines of inclination or dip. 



ISOCTC'LOUS. fr. gr. kuklos. a circle. 

 Applied to animals winch are 



