302 
Labeling, 47 
Latex cavities, 176 
tube cavities, 176 
tubes, 142, 144 
tubes, illustration of, 145 
vessels, illustrations of, 146 
Leaf epidermis, 59 
illustrations, 60, 61 P 
Leaf parenchyma, conduction by, 150 
Leaves, diagnostic structures of, 267 
stomata, 260 
Lenticel, illustration of cross-section, 
159 
Lenticels, zrating function of, 157 
structure of, 158 
Linin, 54 
Long paraffin process, 29 
Machine microtomes, 32 
Measuring cylinder, 40 
illustration, 40 
Mechanical stage, 21 
stage, illustration, 22 
tissue, 89 
Medullary ray, 139 
bundle, 139 
bundle in tangential-section of 
quassia wood, 258 
cell, 141 
cell, arrangement of, in the ray, 
142 
cell, structure of, 142 
cells, in cross-section of quassia 
wood, 254 
cells, in radial-section of quassia 
wood, 258 
cells, in tangential-section of 
quassia wood, 258 
cells, of ruellia stem, 237 
Medullary rays, illustration of cross- 
sections of, 143 
illustration of longitudinal sec- 
tion, 140 
in cross-section of quassia wood, 
254 
in radial-section of quassia wood, 
254 
of pink root, 221 
of ruellia rhizome, 227 
of ruellia root, 223 
of spigelia rhizome, 226 
of white pine bark, 250 
Mesocarp of celery fruit, 285 
INDEX 
Method of mounting specimens, 41 
Micro-crystals, illustrations of, 201 
lamp, 27 
Micrometer eye-pieces, 21 
illustrations, 20, 21 
Microphotographic apparatus, 24 
illustration, 24 
Microscope, how to use, 25 
Microscopic measurements, 19 
Microtome, care of, 36 
Middle bark of white pine, 248 
lamella, 55 
layers of seeds, 291 
Minor rotary microtome, 36 
illustration, 36 
Mountain laurel, cross-section, illus- 
tration of, 265 
Mucilage cavities, 172, 176 
Multicellular hair, 72 
Nuclear membrane, 55 
spindle, 55 
Nucleoli, 55 
Nucleus, 53 
Objectives, illustrations, 11 
Ocular micrometer, 19 
illustration, 19 
Oil cavities, occurrence, 178 
of leaves, 178 
of seeds, 178 
unicellular, 172 : 
Open collateral vascular bundles, de- 
scription of, 298 
Origin of multicellular plants, 57 
Outer bark of white pine, 248 
Palisade parenchyma, conduction by, 
150 
Papillz, 67 
illustrations of, 275 
of stigmas, illustrations of, 276, 
277 
stigma, description of, 274 
Paraffin, blocks, 31 
embedding oven, illustration, 30 
Parenchyma, aquatic plant, 150 
cells of white pine, 248 
conduction by, 144 
cortical, illustrations of, 148 
of mountain laurel, 264 
of trailing arbutus, 264 
pith, illustrations of, 149 
Pericycle of pink root, 221 
of ruellia root, 223 
