MICROSCOPE AND AGRICULTURE 



that, here and there, portions grow erect and bear 

 spores. The spores, it is important to remember, 

 serve the same purpose to the fungus as seeds to 

 the flowering plants. They are blown or carried 

 by insects or other agencies to suitable situations 

 for growth, they germinate and form new fungi. 

 They are smaller and lighter than the most minute 

 and dust-like seeds, so that the slightest breeze 

 scatters them far and wide. Let us compare the 

 white mould with a mushroom; at first sight the 

 two plants appear very dissimilar, in reality they 

 are very similar to one another. The mould forms 

 a thick felt of its threads over the substance on 

 which it grows and mushroom spawn if carefully 

 examined under a microscope will be found to con- 

 sist of very similar threads, sealed together to form 

 thicker root-like structures. The fungi, however, 

 have no roots and these threads are strictly com- 

 parable with those of the mould. Here and there 

 the mould sends a single thread into the air and 

 each of these threads is terminated by a little ball 

 which bursts eventually and sets free its contained 

 spores. The same thing occurs with the mushroom ; 

 we have the upright growth, not of a single thread 

 it is true but of a number, welded together to form 

 a fleshy stalk; at the top there is, not a ball con- 

 taining spores but an umbrella-shaped structure 

 whose under surface is composed of a number of 

 " gills " on which the spores grow at the ends of 

 little stalks. If a piece of the mushroom stem be 

 torn into its separate components and examined 



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