July 11, 1902.] 



SCIENCE. 



55 



ological problems pure and simple, some- 

 where and at some time these problems will 

 be found closely associated with patholog- 

 ical phenomena. 



Reverting' to our Western conditions, 

 arid and semiarid, there are many questions 

 which demand immediate attention and 

 which have an important bearing on the 

 future development of the country. Such, 

 for example, are those which have to do 

 with the water supply of plants and the 

 bearing of water supply on plant produc- 

 tion. Irrigation is now an important fac- 

 tor in our industrial and commercial de- 

 velopment, and the problems associated 

 with it must be reckoned with. In the 

 past the work in this field has been mainly 

 of an engineering nature, such as the ques- 

 tion of securing water and bringing it as 

 economically as possible to the plants. Now 

 arise far more reaching questions, such as 

 how to handle this water in a way to attain 

 the desired maximum results with the least 

 expenditure of time and money. Given 

 water, soil rich in plant food and proper 

 heat and light, the productive power 

 of plants is great if the requisite 

 knowledge is present as to how best to 

 utilize what nature and art supply. Such 

 problems as these must, for the most part, 

 be worked out in the field, but the field 

 must be made to take the part of a labora- 

 tory, for laboratory methods on an exten- 

 sive scale must be emploj'ed. 



What is the effect of varying quantities 

 of water on the longevity of a plant; how 

 is the production of fi'uit and foliage af- 

 fected by the water supply; how far can 

 time of ripening, color, keeping qualities, 

 and resistance to diseases and insect attacks, 

 be controlled through the ability to control 

 the amount of water used? These prob- 

 lems, on their face, appear simple, but they 

 are important ones and to throw light upon 

 them there must be most careful studies in 

 a number of fields. Chemistry will of 



course enter into these studies, but it must 

 be a living, vital chemistry, if I may use 

 such a term, and not the mere question of 

 ash detenninations. Closely related to the 

 problems involved in water supply are those 

 which have to do with so-called alkali soils, 

 and their efi'ects on vegetation. A question 

 of supreme importance to the development 

 of our western country is to imow more of 

 the effects of various mineral salts, sever- 

 ally and combined, on plants. With such 

 complicated problems as present themselves 

 to the investigator in this field, it is not safe 

 to base any conclusions on the knowledge of 

 how plants behave in a laboratory, where 

 the action of a single salt or simple com- 

 bination of salts has been determined. The 

 fact that individual plants show marked 

 differences in their ability to resist the 

 poisonous effects of alkali salts opens up 

 an interesting field in the matter of plant 

 selection and plant breeding. "\\Tierever 

 crops are grown in alkali soils, especially 

 under irrigation, the power of certain of 

 these plants to make better growth and give 

 greater yields than their nearby neighbors 

 has been noted. 



Profiting by these facts, an important 

 field opens in the matter of developing 

 alkali resistant plants, having the power to 

 give relatively large yields in the presence 

 of an unusual amount of soluble salts in 

 the soil. Some interesting suggestions have 

 been made in this direction by the recent 

 work of Kearney and Cameron, and the 

 S3.me investigators have also pointed out 

 the great economic advantages that may 

 result from the combination of two or more 

 salts which, individually, may be danger- 

 ous, but when combined have the opposite 

 effect on plant growth. 



The nature of the problems here briefly 

 reviewed shows the broad scope of physio- 

 logical investigations, for they merge at 

 various places into ecology, pathology, 

 chemistry and physics. There is, further- 



