INDEX 



ABB 



A 



Abbe (Prof.), 011 amplifying power of lens, 

 26 ; on homogeneous immersion, 28 ; 

 011 improvement of optical glass, 32 ; 

 on classification of eye-pieces, 34 ; on 

 principle of microscopic vision, 43, 44, 

 45; on definition of aperture, 44; <>n 

 aperture, 48 note ; on radiation, 57 ; 

 on angle of aperture, 60, 61, 62 ; on 

 diffraction, 63-75 ; on ' intercostal 

 points,' 73; on 'penetration,' 82; on 

 over-amplification, 90; on stereoscopic 

 vision, 90, 94 ; on ' aplanatic system,' 

 94 ; on orthoscopic effect, 95 ; on Rains- 

 deii's circles, 106 ; on solid cones of 

 light, 418 



his stereoscopic eye-piece, 102 ; camera 

 lucida, 281-284 ; apertometer, 307, 

 390-89(5 ; chromatic condenser, 308- 

 309 ; achromatic condenser, 311-312, 

 385 ; condenser, iris-diaphragm fitted 

 to, 312 ; diffraction theory and homo- 

 geneous immersion, 364 ; compensa- 

 tion eye-piece, 378 ; method of testing 

 object-glasses, 384-387; test plate, 

 387-390 ; experiments in diffraction 

 phenomena, 434 



Aberration, 19; positive, 21, 360 note; 

 negative, 21, 27, 360 note; chromatic, 

 31 ; spherical, 31, 301, 306, 388 ; errors 

 of spherical and chromatic, corrected 

 by Ross, 357 



Abies balsamea, 443 



Abiogenesis, 761 



Abraham's prism, 401 



Absorption or dioptrical image, 64 



and diffraction images due to diffrac- 

 tion, 65 note 



- of light rays, Angstrom's law, 323 



- bands, 323-327 

 Abstriction of spores, 633 

 Acaleplice, sexual zociids of polypes, 862 ; 



relationship to hydroids, 872 ; develop- 

 ment of, 874 ; medusan phase of, 877 



Acanthometra xipliicantha, 850; eclii- 

 noides, 852 



Acanthometriiifi, 846, 852 ; central cap- 

 sule of, 852 



Acarina, eggs of, 1004-1006 ; anatomy of, 



ACT 



1009-1012 ; larva? of, 1009 ; nymph of, 

 1009; integument of, 1010; legs of, 

 1010 ; eyes of, 1011 ; classification of, 

 1012 



Accommodation, of the eye, 88 ; depth, 89 

 Aretabularid, 563; pileus of, 563 

 Acetic acid, as a test for miclei, 517 

 Acheta, 987 



cwnvpeatris, eggs of, 1005 



Aclilya, zouspores of, 564 ; oospores of, 

 565 ; zoosporanges of, 640 



proli fera, 563 and note, 563 

 AcJmanthece, characters of, 615 

 Ac-hnanthes, frustules of, 588, 615 ; stipe 



of, 588, 615 ; ' stauros ' of, 616 ; struc- 

 ture of frustule, 615 



Aclinantltes longipes, 615 



Achromatic, comparison of, with chro- 

 matic and apochromatic lenses, 368 



- condenser, Abbe's, 260, 308-312, 314 ; 

 Powell and Lealand's, 301, 311 ; for ob- 

 servation of pyciiogonids, 959 



doublet, Fraunhofer's, 148 ; meniscus, 

 376 



lenses, Charles's, 148 ; Marzoli's, 353 ; 

 Selligue's, 354 



- objectives, 19, 32 ; Tally's, 354 ; Wen- 

 ham's, 361, 362 ; cover slips for use 

 with, 439 



oil condenser, Powell and Lealand's, 

 310, 311 



Achromatism, 17, 19, 150 ; in photo- 

 micrography, 34; rise of, 147; in- 

 augurated, 365 ; imperfect, causing 

 yellowness, 417 



Acineta, 783 



' Acinetiform young ' of Ciliata, 782 note 



Acinetina, 783 ; food of, 783 



' Acorn ' monad, 759 



' Acorn-shells,' 967 



Art inia, reproduction from fragments, 

 863 

 en ml nla, thread-cells of, 879 



- crassiconiis, thread-cells of, 879 

 Aftinocijclus, 588, 610, 620 

 Actinouuua inennc, 850, 851 

 Actinoplirys, 846 



form of Microgromia, 736 



- sol, 737-742 

 Actiuopti/clnts, 588, 610, 611 



1 D 



