154 THK PI. ANT WORLD 



The Resting Period of Plants. 



By C. E. Waters. 



Many persons who go to the woods are often impelled by a strong 

 desire to carry home some of the treasures that they see growing in one 

 of Nature's gardens, and to plant them around their own homes. Such 

 attempts are usually successful with the majority of our wild flowers, 

 although there are a few that will not bear transplanting. It has been 

 found that many species of plants have a ' ' symbiotic ' ' relationship with 

 certain kinds of fungi. That is, the threads, or hyphae, of the fungus 

 attach themselves to the roots of the higher plant, to which they bring 

 certain food materials, while at the same time reaping some benefit from 

 the host. In general, it may be said that all species devoid of root hairs, 

 such as the orchids, the adder's tongue family, and saprophj^tes, possess 

 such root-fungi (^7)iycorr/nza) . But the pines, and heaths, and very 

 many others are more or less dependent on these fungi. It is obvious 

 that unless such plants are very carefully dug up, so as to disturb the 

 roots as little as possible, they will not live in their new home. Besides 

 this, the change of conditions, to which so many species are so sensitive, 

 is also unfavorable to their being transplanted. Other plants will thrive 

 even better in the home garden, where they are taken care of, than in the 

 woods. This is especially true of the wild columbine, which grows to a 

 very large size when planted in any good soil. The leaves are much 

 larger and the flowers more numerous, but the plants we have had under 

 observation die out in about four years, apparently from some sort of 

 decay of the roots. Fresh plants brought in from the woods do not 

 thrive in the spot from which the decayed ones were taken, the soil being 

 inoculated with the disease germs. 



When we try to grow wild flowers indoors, disappointment results 

 if we expect them to do well in winter. It almost invariably happens 

 that the leaves drop off and the plant dies down, just as they do in the 

 woods. The disgusted gardener is then apt to throw them away. The 

 trouble is that we are trying unconsciously to overthrow one of Nature's 

 firmly established laws, that plants need a period of rest during the year. 

 This is certainly true of the plants in temperate regions, and we believe 

 also of the tropics, even where there is no dry season during which they 

 are compelled to stop growing from lack of moisture. 



Even among the lowest plants there are formed so-called ' ' resting 

 spores ' ' that remain inactive for a certain length of time before starting 

 to grow. They are most often formed at the end of the season of growth or 

 on the approach of unfavorable conditions, and can in most cases endure 



