INDEX 



1157 



ICE 



IRI 



'Ice-plant,' epiderm of, 714 

 Ichneumonidte, ovipositor of, 1003 

 Illuminating power, 425 



power of objectives, 54; compared 

 with penetrating power, 393 



Illumination for dissection, 401 



for opaque objects, 149 



oblique, 190, 191, 388 



of objects, Ross on, 300 ; monochro- 

 matic, 321-323 ; Gifford's screen for? 

 321 ; Meithe's filter for, 322 ; Nelson's 

 apparatus for, 323 ; by reflection, 329- 

 338 ; opaque, 329 ; from the open sky, 

 412; by diffused daylight, 412; for 

 dark ground, 413 ; experiments in, 414 ; 

 monochromatic, means of obtaining, 

 417, 418 ; annular, 419 ; colour, 423 ; 

 double, objects for study with, 423 ; 

 with small cones, as cause of errors in 

 interpretation, 427 



Illuminator, oblique, 190; white cloud, 

 194; parabolic, 316-317; Swift's sub- 

 stage, 319; Smith's vertical, 386; 

 Powell and Lealand's, 337; Beck's, 

 337 ; for examination of metals, 337 



Image, real, 14 note ; virtual, 14 note, 876 ; 

 conjugate, 24 ; inverted conjugate, 24 ; 

 absorption or dioptrical, 64 ; diffrac- 

 tion, 64; negative, 64; positive, 64; 

 solid, 95 ; real object, 375 ; definition 

 of, 382 ; formed by compound eye, 984, 

 985 



Images, by diffraction, dioptric and 

 interference, 72 



Imaginal discs in larva of blowfly, 1007 



Imbedding processes, 495-506 ; paper 

 trays for, 497 ; in paraffin, metal case 

 for, 498 ; orienting bottle for, 499 



paraffin method, 409-503 ; in gum, 



475, 505, 506 ; celloidin method, 503- 

 505 



by coagulation or freezing, 505, 506 

 Immersion lenses and vertical illumina- 

 tors, 387, 338 



homogeneous, outcome of Abbe's 



theory of diffraction, 364 



water, Zeiss's, 370 



Amici's, 362 ; Powell and Lea- 



land's, 362, 364 ; Prazmowski and Hart- 



nack's,362; Tolles', 362 



objectives, 28 ; examination of, 387 



system, 27-29 ; invented by Amici, 

 27 



Imperfect achromatism, cause of yellow- 

 ness, 417 



* Impressionable organs ' in Ciliata, 775 

 Incidence, angle of, 3 

 Incident ray, 2 

 Incus of Rotifera, 788 

 Index eye-piece, 381 



of visibility, 521 



Indian corn, epiderm of, 712 ; stomates 



of, 715 



Indirect division of nucleus, 538 

 Indusium in ferns, 675 



Inflection of diverging rays, 62 

 Infusoria, 754-785 ; as food of Actino- 



phrys, 739 ; Ehrenberg's work on, 758 ; 



ciliate, 754, 772 ; unicellular nature of, 



755 note ; character of, 772 

 Infusorial earth, 607, 608, 611, 613, 617, 



620-622 ; from Barbadoes, 846, 849 

 Injected preparations, 1061 

 Inoceramus, portions of shell of, in chalk, 



1087 

 INSECTS, 972-1007 



mounting media for, 973 ; integument 

 of, 974; tegumentary appendages of, 

 974 ; scales of, 975-980 ; hairs of, 980 ; 

 parts of head, 982 ; eyes, 982-987 ; 

 antennae of, 987 ; mouth-parts of, 989 ; 

 circulation of blood, 993 ; alimentary 

 canal, 993; wings of, 994, 998-1000; 

 trachea of, 994; stigmata of, 995; 

 sound-producing apparatus, 999 ; organ 

 of smell, 1000; organ of taste, 1000; 

 feet of, 1000-1002 ; stings of, 1002, 

 1003 ; ovipositors of, 1002, 1003 ; eggs 

 of, 1004 ; agamic reproduction of, 1006 ; 

 embryonic development of, 1007; 

 ' liver ' of, 1047 



parasitic fungi in, 642, 645 



parts of, wooden slides for mounting, 

 450 



Insect work, dark-ground illumination 

 for, 423 ; polarised light for, 423 . 



Integument of insects, 974 ; of Acarina, 

 1010 



Integuments of ovule, 685 



Intensity of light, necessaries for, 417 



Intercellular substance, 1019; in carti- 

 lage, 1046 



Intercostal points, Stephenson on, 73; 

 not revelation of real structure, 73 



Interference, 62 



image, 72 



Intermediate skeleton in Foraminifera, 

 801 ; of Globigerinida, 820 ; of Calca- 

 rina, 825 ; otttotalia, 825 ; of Nummu- 

 lites. 826 ; of Eozoon, 839 



Internal casts of Textularia, 823; of 

 Rotalia, 824; of Eozoon, 840 ; of wood, 

 1083 ; of shells in greensand, 1090 



Interpretation, errors of, 427 



' Interseptal canals ' of Calcarina, 830 



Intestine, cells of villi in, 1044 



Intine of pollen-grains, 720 



Intracellular digestion in zoophytes, 863 



Intussusception, 533 



mode of growth of starch, 694 

 Invagination, 726 



Invertebrata, blood corpuscles of, 1038 



Inverted conjugate image, 24 



Iodine, as a test for starch, &c., 516 



Ipomcea purpurea, pollen-grains of, 721 



Iridescent scales of insects, 975 



Iris, epiderm of, 712 ; leaves of, 717 ; cells 



of pollen-chambers, 720 

 Iris-diaphragm, 297, 313 ; fitted to Abbe s 



condenser, 312 

 Iris germanica, epiderm and stomates ot, 



715, 716 



