Ill 



fingers, and the rock rose and the delicate white of the squinancy- 

 wort (Asperula). Later in the year the heads of the prettier 

 thistles — the carline, the dwarf and musk — relieve the monotony 

 of the grass-land." 



A few words may be added as to lime-shunning plants. The 

 most common of these are the rhododendrons, azaleas, the heaths, 

 and the broom. Wherever these are abundant it is certain that 

 lime is absent. The reason why such plants are intolerant of 

 lime is still in doubt. The roots of many, if not all of them, are 

 covered with a mycelial mantle showing they belong to a group in 

 which there is a physiological partnership with a fungus. It is 

 not impossible that the corroding action of lime is unfavourable to 

 the fungus. If so, the plant cannot obtain its supply of food in the 

 usual way and dies. The subject of what is termed mycorhizal 

 symbiosis is too large to be discussed here ; but it is now recog- 

 nised that there is an important relation existing between the 

 fungus-mycelium and the green-leaved tree or shrub which it 

 provides with water and foodstuffs from the ground whilst it 

 receives in return from its partner such organic compounds as 

 have been elaborated in the green leaves above. 



Use of Lime in Agriculture. 



In the production of farm and garden crops lime is essential, 

 and it exerts a three-fold influence. In the first place it is a direct 

 source of plant food ; in the second place, by its mechanical action, 

 it unlocks and renders available the stores of inert food contained 

 in the soil ; and, lastly, it is valuable on account of its effect in 

 ameliorating the texture of clays and rendering them capable of 

 more successful treatment. As it is admitted that all crops 

 require lime, a soil deficient in this mineral substance can never be 

 a very productive one. It is, possibly, in its second character that 

 lime performs its most important work, namely, by decomposing 

 all kinds of vegetable matter in the soil and correcting acidity due 

 to the presence of organic acids. Farmers and gardeners express 

 this by remarking that " lime sweetens the soil," because it makes 

 the conditions more favourable for plant growth, and encourages 

 the beneficial action of numerous micro-organisms. It is import- 

 ant, however, to bear in mind that lime does not supply the place 

 of organic manures, but only renders that which is already present 

 more easily available for the growth of crops. When used on 

 light dry land like that in the neighbourhood of Bournemouth it 

 tends to make the land drier, since it destroys the humus. 

 Besides its many other merits, lime improves the yield and quality 

 of crops. It destroys injurious insects and checks the growth of 

 moss and weeds. Lime is regarded as the only cure for the 

 disease known as " finger and toe " in turnips and cabbages, 

 while it hastens the maturity of crops. It may thus be realised 

 how various and important is the work performed by lime in 

 increasing the production of all our food crops. 



