14 HANDBOOK OF NATURE STUDY 



prickles. Do they grow out of the wood or from the bark ? 

 Here, on the twigs of the plum and the hawthorn, you can 

 see some real thorns, or spines. See if you can show that 

 they are connected with the wood and are really stunted 

 branches. Of what use might prickles and thorns be to 

 plants ? Examine the stems of young trees and shrubs in 

 any thicket in early spring, and you will find that the rab- 

 bits have peeled off the bark of many species ; that they 

 have cut off and eaten the smooth branchlets of roses, but 

 that they have touched the prickly stems of roses and green 

 brier very sparingly. Can you find evidence that other ani- 

 mals besides rabbits have injured shrubs and young trees ? 

 All our wild roses are hardy shrubs well able to winter 

 in the regions where they grow. They increase by seeds 

 and also by rootstocks. Many garden roses need some pro- 

 tection during our Northern winters. Gardeners generally 

 raise the cultivated roses from slips or cuttings. They also 

 employ grafting and budding on roses and other ornamental 

 shrubs as well as on fruit trees. 



11. Review and Summary. 



We have observed that some flowers do not grow wild, 

 but grow only in our gardens, where we take care of them. 

 If we did not sow or plant them every spring, most of them 

 would soon disappear. Do you not think that many of our 

 wild flowers are so beautiful that they deserve a place in 

 our gardens ? In Europe, our Goldenrods, the Butterfly 

 Weed (a milkweed, Asdepias tuberosa), the Sumach, and 

 other flowers and shrubs are cultivated in gardens. 



Cultivation has brought about many changes in plants. 

 The fruits have become larger and sweeter. In some, as 

 the seedless orange, the seeds have entirely disappeared. 

 In many plants, the flowers have become double and larger, 

 but are often sterile. What change has been effected in 



