INDEX. 



331 



Navicula firma, 141 



lyra, 141 



rhomboides, 103, 117, 118 

 Needles, dissecting, 167 

 Neutral tint re (lector, 205 

 Nitrate of silver staining, 266 

 Nitric acid, 313, 314 

 Nit/schia sigmoidca, 141 



lanceolata, 141 



Nobert's bands, 119 

 Noctiluca miliaris, 137 

 Nodosaria raphanus, 144 

 Nose-piece, double, 60 



Swift's centering, Go 



Numerical apertures, 125 



O. 



OBJECTIVES, 9, 45 



amplifying power of, $3 



Hartnack, 54 



Zeiss, 55 



construction of, 47 



correction of, for photomicro- 

 graphy, 210 



depth of focus of, 114 



homogeneous-immersion, 12 1 



immersion, 104, 121 



improvements in, 46 



low angle, 106 



i -inch, 51 



proposed classification of, 105 



selection of, 49 



separating, 48 



Swift's short mounted, 52 



Wenham's new formula for, 52 



Object of dissecting, 177 

 Objects, collection of, 127 

 delineation of, 203 



by ruled squares, 204 



for polariscope, 248 



Oculars, 40 



American nomenclature, 43 



cleaning, 44 



relative power of, 43 

 Odontophore, 153 

 - of Patella vulgata, 153 

 Oi. I in in aurantiacum, 144 

 Oil-immersion condensers, 68 

 ofcajeput, 317 



Oil of cloves, 317 



of vitriol, 313 



Old works on microscopy, 3 



Opaque injections, 268 



Orbitolites complanatus, 144 



Ordinary ray, 238 



Organisms, life-history of, 3 



Orthoptera, 146 



Orthoscopic eye-piece, Reiner's, 42 



Osborne's illuminator, 74 



Oscillatoria, 132 



Osmic acid, hardening, 314 



staining, 265 



Over-corrected lenses, 106 

 Over-exposed negatives, 214 

 Oxydising agents, 314 

 Oyster, organs of, 179 



P. 



PAPER cells, 284 



Papulaspora sepidonioides, 144 



Parabolic reflector, 79 



Paraboloid, 77 



immersion, 78 



Paramecium aurelia, 129, 134 



Parasitica, 146 



Parasite, spectrum of, 253 



Parmelia parietina, 150 



Patella vulgata, 153, 178 



Pelargonium, petal of, no 



Penetrating power, 103, 113 



Penetration, Abbe's researches on, 1 14, 



"5 



Penicillium crustaceum, 144 

 setophilum, 144 

 Periwinkle, 178 



organs of, 1 79 



Peronospora infestans, 144 



viciae, 144 

 Peronosporites, 201 

 Pertusaria communis, 151 

 Petal of pelargonium, 1 10 

 Petroleum naphtha, 317 

 Petrological microscope, 245 

 Petrology, 246 

 Philodina megalotrocha, 146 

 Phosphoric acid, 313 

 Photographing on wood, 227 

 Photographic varnish, 322 



