LIST OF PLANTS USED FOE STUDY. 469 



Mushroom. See Agaricus campestris. 



Myriophyllum. For growing points, 212. Substitute for Hippuris (q.v.). 



N. 



Narcissus poeticus. For structure of ovule and ovary, 405. Flowers. 



Fresh, or in alcohol. 

 Nasturtium. See Tropceolum. 

 Nettle, stinging. See Urtica. 

 Navicula. See Pinnularia. 

 Nitella. Rotation of protoplasm in, 50 ; vegetative structure, 245. Fresh 



plants. Nitella can be grown in glass vessels of water, especially if 



fed with the culture-fluid given on page 251. 



Reproduction, 309. Plants. Fresh. 

 Nostoc ciniflonum, 262. Fresh. Sometimes found in large olive-green 



masses on damp paths. In some parts of the country known as 



"witches' butter". 



0. 



Oak. See Qiwrcus. 



Oak-gall. See Gall. 



Oat. See A vena sativa. 



(Enothera biennis (Evening Primrose). Pollen-grains and development of 



pollen-tube, 386. Flowers. Fresh. Summer. (As substitutes, 



Epilobium, Fuclisia, q.v.) 



Structure of adherent ovary, 397. Fresh, or in alcohoL 

 Onion. See Allium Cepa. 

 Orange. See Citrus vulgaris (C. Aurantium). 

 Orchidese, Ovary, 392. See Epipactis. 



Embryo-sac, 404. Flowers some time faded. Fresh. (Substitute for 



Monotropa, q.v.) 

 Orniihogalurti unbellatum (Star of Bethlehem). Structure of cell-walls of 



seed, 72. Seeds. Dry. 



Oscillaria, 262. Stagnant water, muddy ground, etc. 

 Osmwnda reyalis (Royal Fern). For germination of spores and formation of 



prothallia, 362. 



P. 



Pceonia (Pseony). Formation of pollen-tubes, 392. Flowers. Fresh. 



Pollen-grains grown in 5 per cent. sol. of sugar, and 1*5 per cent. 



gelatine. 



Pansy. See Viola tricolor. 

 Papavei- Elmos (Field Poppy). Structure of petals, 199. Petals. Fresh, 



or in alcohol. 



Parmelia ciliaris. See Anaptychia. 

 Pea. See Pisum sativum. 

 Pear. See Pyrus communis. 



