56 STATE BOARD OF AGRICULTURE 



seeds of which are preserved from harm by a solid armor and are soon 

 sown broadcast over the land ready to start new colonies. Nuts are 

 often carried by squirrels, a few in a place, for mauy rods and there 

 securely buried. By a slow process which amounts to considerable in a 

 few years, many plants send forth roots, rootstocks, stolons and runners, 

 and thus increase their possessions or find new homes. 



The various devices by which plants are shifted from place to place is 

 not merely to extend and multiijly the si)ecies and reach a fertile soil, but 

 to enable them to flee from the great number of their own kind, and their 

 enemies among plants and parasitic plants. The adventurers among 

 plants often meet with the best success, not because the seeds are larger 

 or stronger or better, but because they find for a time more congenial 

 surroundings. Our weeds are good illustrations of this point. They are 

 carried for long distances by man and by him are planted in new ground 

 that has been well prepared. Every horticulturalist knows that apples 

 grown in a new country, if suitable for apples, are fair and healthy, but 

 the scab and codling moth and bitter rot and bark louse sooner or later 

 arrive, each to begin its peculiar mode of warfare. Peach trees in new 

 places remote from others are often easily grown and free from dangers, 

 but soon will arrive the yellows, borers, leaf curl, rot, and a number of 

 other enemies to combat. For a few years plums are grown without 

 danger from curculio or rot or shothole fungus. It has long been known 

 that the surest way to grow a few cabbages, radishes, squashes, cucum- 

 bers or potatoes is to plant them here and there in good soil at consider- 

 able distances from where any have heretofore been grown. For a time 

 enemies do not find them. I have often noticed that while pear blight 

 decimated or swept off large portions of a pear orchard, a few isolated 

 trees scattered about the neighborhood — many neighborhoods — usually 

 remain healthy. The virgin soil of the Dakotas produced at a trifling ex- 

 pense healthy, clean wheat, but it was not long before the Russian thistle, 

 false flax and other pests followed to contest their rights to the soil. If, 

 as in endemic species, they seem for some reason to be much restricted, 

 they are very likeh' to become extinct and give waj' to those not so re- 

 stricted. Perhaps one reason why some plants have become extinct or 

 nearly so is their lack of means of migration. As animals starve out in cer- 

 tain seasons when food is scarce, or, more likely, migrate to regions 

 which can afford food, so plants desert worn-out land and seek fresh 

 fields. As animals retreat to secluded and isolated spots to escape their 

 enemies, so many plants accomplish the same thing by finding the best 

 places with some of their seeds sown in many regions. Frequent rotations 

 seem to be the rule for many plants when left to themselves in a state of 

 nature. Confining to a permanent spot invites parasites and other 

 enemies and a depleted soil, while health and vigor are secured by fre- 

 quent migrations. 



THE WEED GARDEN. 



For about five years past, the Botanical Department at Michigan Agri- 

 cultural College has maintained a weed garden in which one hundred 

 species or more, of our most troublesome weeds are grown in plots, each 

 five by six feet, and all plainly labeled with common and scientific names. 

 For ten years previous a smaller garden was maintained for a portion of 



