THE ADVANTAGES OF AN ARBORETUM. 59 



diagrams — that it is impossible for the pollen of a flower to get to the intended 

 place without help from insects or other artificial means. Wind can not do it 

 in this case. This is exceedingly strange, when we see the stamens full of 

 pollen within a quarter of an inch of the tip of the pistil. Large numbers of 

 plants, as the orchids and milkweeds, have the same peculiarity. This brings 

 up a vast field for experiment and study. 



I have experimented with many hundreds of flowers of different plants, 

 repeating what others had done, and making new discoveries. You can make 

 squashes come true to seed every time, I do not care how many kinds there are 

 together, if you carry the pollen yourself to a young flower and then tie it up 

 to keep off the insects. 



Many flowers are known to be self-fertilizing. A few rare cases are known 

 in which plants will have good seeds which will grow, even without any 

 fertilizing by pollen. In one case a plant was taken from Australia to Eng- 

 land. It was of a kind which bears only pit^tillate flowers on one plant and 

 only staminate flowers on others. Our willows and poplars all have such 

 flowers, and the diflt'rent sexes are often some distance from each other. 



The pistillate plant spoken of had no stamens nearer than Australia, yet it 

 bore seeds which grew. The plant was carefully hunted over repeatedly by 

 good observers, without ever finding a stamen. Seeds from this p'ant in Eng- 

 land produced plants which were nearly all pistillate, whereas seeds raised on 

 plants which Had been fertilized were about equally pistillate and staminate. 



This brings up the whole matter of hybridizing and crossing plants artifi- 

 cially at the will of the experimenter. There are real principles in such 

 experiments, as important for the horticulturist to know as for the agriculturist 

 to understand the principles of stock-breeding. Both will experiment at 

 random with little chance of success unless he understands these principles. 



