SPECIAL MANURES 217 



The climate of a country is all important. It is 

 well known how much sooner cherries, plums, etc., 

 ripen in the south of Europe than in this country ; 

 however, sometimes the climates of countries are 

 such that places farther north wUl grow trees better 

 than others more to the south. This, owing to the 

 warmth diffused by the Gulf Stream, so alters the 

 climate of Sweden that the lilac shows its leaves 

 earlier at Upsala than in Paris ; the laurustinus 

 grows better in London than at Lyons, owing to 

 the severe cold which characterises the winter in 

 the latter place,^ whilst that of the former is more 

 equable. 



Limes. Although devoid of brOliantly coloured 

 flowers, these trees emit a delicious perfume, and 

 modern biologists attach great importance to cross- 

 fertilisation by insects, the latter being attracted 

 by the odours of the flowers, etc.^ Insects appear 

 to possess " a language of smeU," and the late Dr. 

 Piesse showed that perfumes can be chorded like 

 musical notes, so that entirely new odours may be 

 the result, as in eau-de-Cologne. Lime-trees 

 would be practically helpless without the powerfully 

 fragrant flowers which they possess. The perfume 

 is sufficiently attractive to bees to enable them to 

 do without gay or bright-coloured flowers. 



' See A. B. Griffiths' The Physiology of the Invertebrata. 



