PHENOMENA OF PLANT-LIFE. 205 



Fourth. The structure and functious of the bark of ex- 

 ogenous trees, with special reference to the circulation of sap, 

 the formation of wood and the effects of girdling, — concerning 

 all which points many experiments have been undertaken 

 with satisfactory results. 



Fifth. An attempt has been made to measure the expan- 

 sive force of growing vegetable tissue, and in connection with 

 this experiment numerous other interesting observations have 

 been reached. 



These investigations have been instituted by myself ; but in 

 carrying them out, I have enjoyed the valuable, and, in many 

 cases, indispensable, assistance of gentlemen connected with 

 the Agricultural College, either as officers or students. Due 

 credit will be given to each in stating the results of his 

 work. 



To succeed as an original investigator in science, one must 

 possess some of the noblest qualities of mind and heart. He 

 must be absolutely and accurately honest, and in his methods 

 of demonstration there must be no guess-work. He has need 

 of a patience which is inexhaustible, a zeal and energy which 

 never flag, and a spirit of devotion to his work which utterly 

 ignores self as separated from the object to be accomplished. 

 He must also have a well-disciplined mind, and skill in the 

 use of books and apparatus. To produce such men, who 

 shall, at the same time, be familiar with all the great princi- 

 ples and problems of agriculture, is the highest possible 

 achievement of our College. One such graduate will do more 

 for the advancement of the art, and the honor of the profes- 

 sion and the benefit of mankind, than would a host of mere 

 farm-apprentices possessed only of manual skill and a knowl- 

 edge of simple, routine practice, however well adapted to any 

 particular locality or style of farming. 



I am well aware that there are persons who hold a respect- 

 able position in society, and yet are so ignorant as to regard 

 with contempt all efforts at scientific research. They ridicule 

 the attachment of gauges to trees, and the harnessing of 

 squashes, and the microscopic and chemical analysis of plants, 

 as of no earthly use, except, perhaps, to gratify an idle 

 curiosity. But how shall agriculture be improved without 

 the application to it of the principles of science ; and how 



