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perties of the soil. More recently another school has developed in 

 which the physical properties of the soil are pointed out as the chief 

 factors in influencing life processes. Those who study plants them- 

 selves cannot accept such oreneralities. It is not safe. Future ecolo- 

 gical studies will undoubtedly furnish much new light on the true re- 

 lationships existing between plants and their environment. These 

 questions must naturally receive a great deal of attention for the rea- 

 son that many of the most important problems in agriculture, horti- 

 culture and forestry will be based upon them. 



It is in pathology that we shall expect to see very important ad- 

 vances within the near future. This science is just on the threshold 

 of its development. From the purely utilitarian standpoint it will be 

 of vital consequence, and everything in the nature of strengthening it 

 will necessarily need to receive most careful thought. The pathology 

 of the future will have its groundwork in physiology. Less and less 

 attention will undoubtedly be given to the mere question of remedial 

 measures, and more thought will be paid to the causes of plant diseases 

 and the relation of environment to these causes. The highest type of 

 pathological work, in other words, will be in the field of preventive 

 measures, either by the correction of unfavourable conditions or by 

 developing plants in such a way that they can meet conditions which 

 are not favourable. 



THE RELATIONS OF PLANTS TO BIRDS AND 



INSECTS.* 



By Elizabeth G. Britton. 



It may not have occurred to many of our readers to associate the 

 movement for the preservation of our native plants with the work of 

 the Audubon Association and the Entomological Department at 

 Washington, but there is no question that much of the change in the 

 number and habits of our native birds is due to the changes made by 

 man in the extermination of the native plants on which they feed, 

 and that many of the insecticides which are so largely in use in agri- 

 cultural communities are made necessary by the destruction of the 

 natural eremies of the insects, the birds, and that they in turn do 

 much to drive the birds away. That the Valance of life can not be 

 disturbed in any given region without causing countless unforeseen 

 changes is best illustrated by Darwin's story regarding the connection 

 between the clover, bumble-bee, mice, cats and old maids. The cat 

 has also become a strong disturbing factor in the extermination of 

 our wild birds, and combined with the destruction of native trees, 

 shrubs, and herbaceous plants, the surroundings of all our cities and 

 towns will account in a great meas-ure for their disappearance. Some 

 of the worst insect pests are not natives here, and it takes some time 

 for the native birds to learn to like them. 



It has been found that when the Colorado beetle or potato-bug 

 started on its progress eastward, it met with but little resistance until 

 it reached the State of Iowa. Here, so the story is told, a farmer no- 

 ticed that after anointing his potato vines with Paris green a number 

 of rose-breasted grosbeaks lay dead on the ground in the morning. 



* The Plant World, Vol. VII; No. 3, 1904. 



