240 Gttests Welcome and Unwelcome 



proceed without delay to climb some other plant 

 whose blossoms are beginning to give fragrant notice 

 that another pleasant guest-chamber is ready for their 

 reception. Thanks to this diligence, therefore, pollen 

 is brought to the pistils, as soon as they are ready for 

 it, by the ' fastest snail-express.' 



Hitherto we have confined our attention to the 

 welcome guests ; but there are unwelcome ones also, 

 and the very snails last considered have two sides to 

 their character. Indeed, the beneficent side is not the 

 one with which we are familiar, being rather a recent 

 discovery, while their mischievous propensities are 

 well and widely known. Even the arums which 

 welcome them as pollen-carriers need some sort of 

 protection against them. They have to be tempted 

 to undertake what to them is really an immense 

 journey, by special attractions, otherwise, being 

 voracious eaters, they would simply begin to devour 

 the first leaf they came across. Then, when they have 

 started, all loitering by the way is sternly discouraged, 

 for arum-leaves are acid, and even poisonous ; so there 

 is no temptation to make a meal of them. 



Useful as they are to arums and arum-like plants, 

 they are not generally desirable as visitors, and are not 

 often found in flowers, bristles and prickles being 

 enough to turn them back at once. No wingless 

 visitors are generally welcome, for they crawl slowly, 

 lose pollen by the way, by getting it rubbed off them, 

 and are usually so indiscriminate in their tastes, that 

 they go as readily to one blossom as another, and it is 

 quite a chance what pollen, if any, they may bring 

 with them. 



