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On the Principal Questions at present debated in the Philoso- 

 phy of Botany. By John Lindley, Ph.D., F.R.S., %c., 

 Professor of Botamy in the University of London. 



If we compare the state of Botany at the end of the last cen- 

 tury with its present condition, we shall find that it has become 

 so changed as scarcely to be recognised for the same science. 

 Improvements in the construction of the microscope, the disco- 

 veries in vegetable chemistry, the exchange of artificial methods 

 of arrangement for an extended and universal contemplation of 

 natural affinities, the reduction of all classes of phaenomena to 

 general principles, and, above all things, the adoption of the 

 philosophical views of Gothe, together with the recognition of 

 an vmiversal unity of design throughout the vegetable world, 

 are undoubtedly the principal causes to which this change is 

 to be ascribed. 



As the general nature of recent discoveries, and a sufficient- 

 ly definite notion of the present state of botanical science, may 

 be collected from the introductory works which have appeared 

 in this country within the last three years, it is presumed that 

 the object of the British Association will be attained if the 

 present Report is confined to the most interesting only of those 

 subjects upon which botanists have been recently occupied, 

 and to an indication of the points to which it is more particularly 

 desirable that inquiries should now be directed. I have also 

 excluded everything that relates to mere systematic botany, in 

 the hope that some one will take that subject as the basis of a 

 separate Report. 



Elementary Organs. — This country has, till lately, been re- 

 markably barren of discoveries in vegetable anatomy, since the 

 time of Grew, who was one of the fathers of that branch of 

 science. Whatever progress has been made in the determina- 

 tion of the exact nature of those minute organs, by the united 

 powers of which the functions of vegetation are sustained, it 

 has been chiefly in foreign countries that it has taken place : 

 the names of Mirbel, Moldenhauer, Kieser, Link and Amici, 

 stand alone during the period when their works were published ; 

 and it has only been within a very few years that those of 

 Brown, Valentine, Griffith and Slack have entered into com- 

 petition with the anatomists of Germany and France. 



By the researches of these and other patient inquirers, we 



