424 Prof. C. Timiriazetf'. [Apr. 30, 



CROON IAN LECTURE. " The Cosmical Function of the Green 

 Plant." By C. TIMIRIAZEFF, Professor of Botany in the 

 University of Moscow. Communicated by Sir M. FOSTER, 

 Sec. R.S. Received April 30, Lecture delivered April 30, 

 1903. 



[PLATES 2022.] 



The first object which attracted Gulliver's notice when on his visit 

 to the Academy of Lagado was a man of " meagre appearance," his 

 eyes fixed on a cucumber sealed in a phial. On Gulliver's questioning 

 him, the strange personage explained that for more than 8 years he 

 had been absorbed in the contemplation of this bit of apparatus, trying 

 in vain to solve the problem of the storage of the sun's rays in this 

 recipient and their possible utilisation. 



Now, to begin with, I must frankly confess that I am just that sort 

 of man : for 35 years have I been staring, if not exactly at a cucumber 

 in a phial, still at what comes to the same thing, at a green leaf in a 

 glass tube, and breaking my head in vain endeavours to clear up the 

 mystery of "bottled sunshine." If I venture to bring before this 

 illustrious Society the modest results of this long-continued work it 

 is in the hope that this theme may have a real, though very distant 

 connection with the subject which Dr. Croon, the generous and en- 

 lightened founder of this lectureship, considered as most fit for the 

 occasion. During a long series of years the chief topic of these 

 lectures was " Muscular Motion," and at a more recent period 

 " Motion in Animals and Plants," and " The Origin of Vital Move- 

 ments " in general. Perhaps I may be allowed to take a step further 

 in this direction in fact, the last possible step, and speak of the energy 

 manifested in all these movements, of its remotest source the sunbeam 

 stored in the green plant. 



I suppose it is hardly necessary to remind you that the ground we 

 are going to tread has been explored in this country and America for 

 more than a century. Suffice it to call to mind the familiar names of 

 Priestley, Count Rumford, Daubeny, Sir David Brewster, John William 

 Draper, Sir John Herschel, Robert Hunt, Sir George Gabriel Stokes, 

 Mr. Edward Schunck, Mr. Sorby, Sir William Abney, Mr. Blackmail, 

 and last not least Mr. Horace Brown, to show what interest this 

 question has continued to inspire under its various aspects. I may add 

 that it was in Professor Tyndall's brilliant " Heat a Mode of Motion" 

 and in my resultant study of Robert Mayer's classical work " Die 

 organische Bewegung in ihrem Zusammenhange mit dem Stoffwechsel," 

 that I found the first impulse towards all my subsequent work. And 

 it must be admitted that the moment was singularly propitious : 



