INDEX 



1165 



xuc 



oos 



Nucleus, 534 



action of acetic acid on, 517 ; its im- 

 portance to cell, 535 ; division of, 538 ; 

 fragmentation of, 538 ; presumed ab- 

 sence of, in some forms, 727 ; initiative 

 action in monads, 762 



and cell division, 1019 note 

 Nucule of Chara, 577, 579 

 Nudibranchs, nidameiitum of, 934 ; em- 

 bryos of, 936 



Numerical aperture, 29, 53, 60, 390, 

 425 ; formula for, 390 ; problems on/ 1 

 391 



of dry objective, 391 ; of water- 

 immersion, 391 ; of oil-immersion, 391 



and resolving power of objective, 



393 



apertures, table of, 84-87 

 Nummuline layer of Eozoon, 840 



plan of growth, Parker and Rupert 

 Jones on, 827 note 



Nummulinidce, 826 

 Nummulites, 826, 827, 831 



distans, 832 



garansensis, 832 



Icevigata, 832 



striata, internal cast of, 834 



tubuli in shell of, 800 

 Nummulitic limestone, 831, 835, 1085, 



1090 

 Nuphar lutea, parenchyme, 687 ; stellate 



cells of, 687 

 Nymph of Acarina, 1009 ; of Oribatidte, 



1009 



O 



Oak, size of ducts in, 699 



- galls, 1003 



Oberhiiuser's spiral fine adjustment, 153 



Object-glass of compound microscope, 

 36, 39 ; of long focus, 40 ; of short 

 focus, 40 ; capacity of, 382 



Object-glasses, power of, 44 



- testing, 381; Abbe's method of 

 testing, 384-387 : diaphragms for use 

 in testing, 385 ; Fripp's method of 

 testing, 386 



Object-holder for Thoma's (Jung's) mi- 

 crotome, 464, 465, 466 



changer, Zeiss's, 293 



Objectives, achromatic, 19, 32; aplanatic, 

 19 ; apochromatic, 19, 30, 34, 80 ; cor- 

 rected, 20, 21 ; immersion, 28, 34, 58 ; 

 aperture of, 43, 65, 390; maximum 

 aperture of, 44 ; comparison of, 46 ; 

 illuminating power of, 54 note ; im- 

 mersion v. dry, 54, 79 ; dry, with balsam 

 mounted objects, 55 ; dry, 58; dry, for 

 study of life-histories, 81 ; penetrating 

 power of, 83, 393 ; sliding plate with, 

 290 ; rotating disc with, 290 ; of wide 

 aperture, 369 ; of small aperture, ex- 

 amination of, 388 ; tests for, 388, 394 ; 

 resolving power of, and numerical aper- 

 ture, 393 



Objectives, triple-back, 361; Wenham's 

 single front, 361 ; duplex front, 362 ; 

 Leitz's, 374; Reichert's, 374; adjust- 

 ing, 357, 360 



achromatic, Martin's, 147 ; Marzoli's, 

 353; Tully's, 354; Selligue's, 354; 

 Amici's, 355 ; Ross's, 356, 360 ; Powell's, 

 356, 361 ; Smith's, 356, 360 ; Wenham's, 

 361 ; covers for use with, 439 



apochromatic, 366, 370, 371-375 



homogeneous immersion, introduction 

 of, 364 



' semi-apochromatic,' 35, 374, 375 



oil-immersion, Powell and Lealand's, 

 30 ; Amici's, 364 ; Tolles', 364 ; 

 Zeiss's, 370; Leitz's, 374; Reichert's, 

 374; Swift's, 375; Beck's, 375; 

 Bausch and Lomb's, 375; Watson's, 

 375 



water-immersion, Powell and Lea- 

 land's, 362, 365 ; Prazmowski and Hart- 

 nack's, 362 ; Zeiss's, 370 



Oblique illumination, 190, 191, 387 



illuminator, 190 



Obliteration of structure by diaphragms, 

 68 



Occhiale, Galileo's, 122, 123 



Occhialino, Galileo's, 121, 124 



Oceanic sediinents, microscopic examina- 

 tion of, 1092 



Ocelli of planarians, 947 ; of insects, 982, 

 986 



Ocellites of compound eye, 982 



Ocular, 40, 375 ; spectral, 327 



(Edogoniaoece, 572 



(Edogonium ciliatum, 573 



(Enothera, pollen-grain, 721; emission 

 of pollen-tubes of, 722 ; embryo of, 723 

 j Oil for immersion lenses, suggested by 

 Amici, 29 



of cedar-wood, for immersion objec- 

 tives, 29 



Oil-globules, 429-431 

 Oil-immersion, 29 



- objectives. See Objectives, oil- 

 immersion 

 j Oils, solvents for, 517 



Okeden, on isolation of diatoms, 624 



note 

 Oleander, epiderm of, 714 ; stomates of, 



716 



Olivine, corroded crystals of, 10,72 

 Onchidium, eyes of, 941 

 ' Oncidium, spiral cells of, 693 

 j Onion, raphides of, 696 



Oogones of Vaucheria, 563 ; of Sphere- 

 plea, 572 ; of (Edogonium, 572 ; of 

 Chara, 577 ; of Fucacece, 627, 628 ; of 

 Peronosporece, 638 

 | Oolitic grains, 1084 



Oophyte in ferns, 680 



| Obspheres, use of the term, 537 note ; of 

 Volvox, 556; of Vaucheria, 563; of 

 Sphceroplea, 570 ; of (Edogonium, 572 ; 

 of Chara, 577 ; of Phceosporece, 627 ; 

 of Fucacece, 628 ; of Marchantia, 668 ; 

 of ferns, 679 



