INDEX 



1149 



DIA 



DYT 



markings of, 593 ; binary division 

 of, 594-597 ; reproduction of, 594-601 ; 

 placochromatic, 598 ; coccochromatic, 

 598 ; conjugation of, 599 ; zygospores 

 of, 599 ; gonids of, 599 ; movements of, 

 601 ; classification of, 602 ; habits of, 

 619 ; habitats of, 620 ; distribution of, 

 621 ; fossil forms of, 622 ; used as 

 food, 622 ; collecting, 622 ; cleaning, 

 623, 624 note ; mounting, 624 ; as food 

 of Ciliata, 775 ; in mud of Levant, 

 1085 



Diatom-frustules in ooze, 1086 



Diatomin, 587 



Diatoms in stomach of ascidians, Holo- 

 thurice, &c., 614, 623 



Diatoms. See DIATOMACE.& 



Dichroism, 1098. See PLEOCHBOISM 



Dickiea, 602 



Dicotyledonous stems, fossilised, 1083 



DICOTYLEDONS, 700 ; stem of medullary 

 rays of, 702 ; epiderm of, 712 



Dictyocalyx pumiceus, 861 



Dictyochya fibula, 620 



Dictyocysfal) silicious shell of, 773 



Dictyoloma peruviana, winged seed, 

 724 



Dictyospyris clathrus, 847 



Dictyota, ob'spheres of, 627 



Didemnians, 914 



Didymium serpula, plasmode of, 635 



Differential screw, Campbell's fine ad- 

 justment, 162, 164, 165, 174, 202, 230 



Differential staining, 493 



Differentiation of cell, 533 



Difflugia, 746; test of, 746 



.Diffraction, 62 



Abbe's theory of, and homogeneous 

 immersion, 363 



Fraunhofer's law, 57 



rays are image-forming, 59 



spectra, 28, 67 ; phenomena, 62, 64 ; 

 image, 64, 72 ; experiments, 66-70 ; fan 

 of isolated corpuscles, 72 ; problem, 73 ; 

 pencil, 74, 75 ; hypothesis of Abbe, 74 ; 

 fan, 75 ; theory, application of, 76, 78 ; 

 bands, 277 ; phenomena, Abbe's experi- 

 ments, 434 ; ghost, 435 



Digestive vesicles of Ciliata, 776 



Digitalis, seeds of, 724 



Dimorphism in Foraminifera, 802 



Dinobryon, 765 



Dinoflagellata, 770 



Diiiomastigophora, 770 note 



Dioptric investigations by Gauss, 106- 



110 



Dioptrical image, 30, 72 

 Diorite, fluid inclusions in, 1074 

 Dipping tubes, 350 

 Diptera, 973 ; eyes of, 987 ; antennae of, 



988 ; mouth-parts of, 990 ; wings of, 



998 ; ovipositor of, 1003 ; imaginal discs 



of, 1007 



Direct division of nucleus, 538 

 ' Directive vesicles ' of egg of Purpura, 



937 

 Disc-holder, Beck's, 339 



Discida, 849 



Discoliths, 748, 749 ; artificially produced, 



1101 

 Discorbina, 824 



globularis, 798 

 Disintegration of rock-masses, 1076 

 Dispersion, 9, 17 ; in glass, 31 



and desiccation of encysted Ciliatcu 

 781 



Dispersive power, 2, 9, 18 ; of flint glass. 



10 

 Dissecting apparatus, 455 



microscope, Greenough's binocular, 

 248; Stephenson's binocular, 248; 

 Huxley's, 251 ; Zeiss's, 251, 253 

 Bausch and Lomb's, 252 



Distance of projection of image, 26, 27 

 Distinct vision, 26 

 Distoma, life-history of, 946 



hepaticum, 945 

 Divergence of light, 18 



Divini's compound microscope, 129 

 Division, binary, of cells, 535 ; of desmids, 

 582 



artificial, of Actinosphcerium, 741 note 



of naiads, 955 

 Dobie's line, 1049 

 Dog-fish, scales of, 1028 



D'Orbigny, on plan of growth of Fora- 

 minifera, 799 



Doris, spicules in mantle, 928, 929 ; nida- 

 mentum of, 934 ; eggs of, 942 ; spines 

 of, imitated, 1101 



bilamellata, development of, 935- 

 937 



pilosa, palate of, 931 



tuberculata, palate of, 931 



Double illumination, Stephenson's me- 

 thod, 105 



Doublet, Wollaston's, 36, 153 

 Dragmata, of sponges, 860 

 Dragon-flies, wings of, 998 

 Dragon-fly, facets in eyes of, 983 



See Libellula 

 Draparnaldia glomerata, 574 

 Draw-tube of microscope, 157 

 Drebbel's modification of Keplerian 



telescope, 121 



Dredge, 528 



Drepanidium ranarum, 752 



Drone-fly. See Eristalis. 



Dropping-bottle, 476 ; German, 477 ; ex- 

 pansion, 477 



Drosera, glands of, 714; seeds of, 724 



Dry-mounting, Smith's ' cells ' for, 446 



Ducts of Phanerogams, 698 



Dudresnaya, fertilisation in, 632 ; ferti- 

 lising tubes, 632 



Dujardin, on ' sarcode,' 530 note 



separates Amoeba from Infusoria, 

 733 



Dunning's zoophyte trough, 348 

 Duramen, 704 



Dwarf-male of CEdogonium, 572 

 Dytiscus, eye of, 987 ; antennae of, 988 ; 



spiracle of, 996 ; trachea of, 996 ; foot 



of, 1001, 1002 



