314 <; LEANINGS FEON NA TURE. 



one-celled bodies, having a much thicker coat and 

 denser, protoplasm or contents than are found in the 

 spores often produced in summer by the same plants, 

 and which are destined for immediate growth. The 

 power of life within these winter resting spores is 

 proof against the severest attacks of frost, and they 

 lie snugly ensconced in the mud at the bottom of pond 

 or stream, or buried beneath the leaves in some shel- 

 tered nook, until the south winds of 

 Rusts and Fungi A/r -, A ., ~ . , ,1 i 



i Wi t March or April furnish the key to 



unlock the castle of the ice kin<jf. 

 Then the spirit of growth within each spore begins to 

 assert itself once more, and, bursting the walls, the 

 contents soon produce the parent or summer form of 

 the plant with which we are most familiar. Thus the 

 spores which the next season will produce the grape 

 mildew and the red rust of wheat exist throughout 

 the winter the former within the substance of the 

 fallen grape leaf, the latter within the stubble or about 

 the roots of the last season's wheat plants. 



If the grape leaves should be carefully gathered 

 and burned, and the stubble destroyed in like manner, 

 not only would the next season's crop of these two 

 parasitic plant pests be wonderfully lessened, but 

 many injurious insects would at the same time be 

 destroyed. 



Higher in the scale of plant life we find the flower- 

 ing annuals bending all their energies during the 

 summer to produce that peculiar form, the "seed." 

 which is only a little plant boxed up to successfully 

 withstand the rigors of winter. The great sunflower, 

 that grows into a giant in a single season and defies 



