476 
Morchella (morel), 851*, 552 
Morning glory, 168 
Morphology, 1; comparative, 261-263 
Morus alba (mulberry), fruit of, 272* ; 
leaves of, 26*, 155*; lenticel forma- 
tion of, 98*, 154% 
Mosaics, leaf, 112 
Moss, 379%, 449-450, 452* ; peat, 382 ; 
reindeer, 366. See Musci 
Motile leaves, 91-92 
Motile organs, 262 
Mountain vegetation, 446-450 
Movement in protoplasm, 21-22 
Mucilage, 77 
Mucor mucedo, 349* 
Mucuna gigantea, seeds of, 286* 
Mucuna pruriens (cowitch), hair of, 75* 
Muehlenbeckia platyclada, specialized 
stem of, 169* 
Mulberry (Morus alba), fruit of, 272*, 
277; leaves of, 26*, 155* ; lenticels 
of, 98*, 154* 
Mungo bean 
110* ; cells of, 289% ; 
195*, 196*, 197* 
Muntingia calabura, stem of, 144*; 
flower of, 205* 
Musa textilis, 182 
Musci, 367, 380-382 ; and Anthocero- 
tales, 380; life history of, 880-881 ; 
relationship of, 381-382 
Mushrooms, 363 
Mutations, 250-252, 258 
Mycelium, 345 
(Phaseolus radiatus), 
root of, 192*, 
Natural selection, 256-259;  signifi- 
cance of sexuality, 258-259 ; struggle 
for existence, 256-257; survival of 
the fittest, 257-258 
Neck cells of Cycadales, 409 
Neck-canal cells, of fern, 389-392 ; of 
Riccia, 368, 369* 
. Nectar, 218 
Negative geotropism, 108 
Negative phototropism, 109 
Nelumbium nelumbo (lotus), 286*, 459* 
Nemalion, sexual reproduction in, 343* 
Nepenthes, leaf of, 83* 
Nerium oleander, cork of, 152* ; section 
of leaf of, 62* 
Netted veins in leaf, 28 
Nettle (Laportea meyeniana), stinging 
hair of, 75* 
Nipa fruticans, 24 
Nitrogen, and humus, 189 ; in proteins, 
18, 80, 175 
A TEXTBOOK OF GENERAL BOTANY 
Nitrogen-fixing bacteria, 307-308 
Nodes, 60*, 96 
Nodules, 308* 
Nostoc, 313*, 314* 
Nucellus, 221-222, 404, 409 ; of angio- 
sperms, 430; of pine, 422-423; of 
Spermatophyta, 407. See Megaspo- 
rangium 
Nuclear membrane, 224 
Nucleolus, 224 
Nucleus, 20, 228; in bacteria, 306; di- 
vision of, in orchid, 429* ; in flower, 
221-231; male, of Spermatophyta, 
405 
Nut, 278 
Nymphaea stellata (water lily), cross 
section of petiole of, 54* 
Oak (Quercus bennettii), wood fibers 
of, 120* 
Oats, 218, 254 
Odors, 77; of flowers, 220 
Oedogonium, 324-828 ; relationship of, 
327-328 ; reproduction in, 324-327 ; 
vegetative structure of, 324 
Oil, 49, 77, 292%, 298%, 294* 
Oils, essential, 220 
Olein, 291 
Onion, 89, 204; bulb of, 89* ; root of, 
23*, 179*, 194* 
Onion smut, 355* 
Oédgonium in Saprolegnia, 345 
Odmycetes, 344-351 ; and Zygomycetes, 
349 
Odspore, 326 
Operculum, 382* 
Opium, 128 
Opposite leaves, 101 
Optimum temperature for growth, 
160-161 
Opuntia, 456* 
Orange, 77, 125*, 128, 258, 279 
Orchid, 11, 115, 199, 486; Cymbidium 
Jinlaysonianum, 282*; Dendrobium 
anosmum, 108* 
Order, 211 
Organic evolution, 260 
Organisms in soil, 189 
Orientation, 303 
Oryza sativa (rice), 355* 
Oscillatoria, 310* 
Osmosis, 89-42; of colloids, 142; in 
plant cells, 41-42 
Osmotic pressure, 39-42; in guard 
cells, 69-70 ; in root, 188 ; and tran- 
spiration, 57-59 
