354 INDEX. 



near l,oiidon, 128 — effect of, on pollen, 111 — necessary to pro- 

 duce germination, 8 — of the soil, 113 — abundant supply of, re 

 quired by plants in a growing state, 114 — effects of an exces- 

 sive supply of, 115 — of hothouses, its regulation, 142 — an excesi 

 of, prejudicial to plants in a rapid state of growth, 148 — rules 

 for its adaptation, 149 — preserved by means of oiled paper, 155 

 — necessary to germination, 1 60 — its tendency to produce decay 

 in seeds, 163 — should be sparingly applied to the roots of trees 

 previously too much dried, 294. 



Monstrosity a cause of sterility, l73^-cause3 inducing it, 316. 



Mules, their origin, 68. 



Muling, 310. 



Muling, limits of its operation, 312. 



Muriate of lime, its use for the preservation of seeds, 176. 



Muriate of soda, its free absorption by roots, 17. 



N. 



Nitrogen, in spongioles, 13 — in seeds, accelerates their vegetation, 19 

 — indispensable for the first formation of tissue, 19 — a compo- 

 nent of the food of plants, 18 — in plants, is extricated by solar 

 light, 41 — its abundance in young tissue, 18. 



Night, diminution of the functions of plants in the, 327. 



Nodules in the bark of trees, 31. 



Nutritions matter, in plants, influences the production of flower- 

 buds, 65. 



O. 



Oleraceous annuals, 118. 



Orange tree, natural temperature of the soil for, 104. 



Orange tribe, drainage for their roots necessarily beneficial, 276. 



Ovary, and ovules, 56. 



Oxalic acid employed to promote the germination of old seeds, 167. 



Oxygen is absorbed from water during the process of germination, 8 

 — in plants, 18— derivation of its supply, 18 — excess of, in 

 certain vegetable secretions, 75 — employed to promote germi- 

 nation, 167 — is absorbed by leaves when their functions beconii 

 languid through age, 54. 



P. 



Pan feeders, 269. 



Parasitical fungi suppond to lay hold of diseased tissue only, SI. 



