145 



[TAB, XLIL] 



LEMNA GIBBA. 



REMARKS ON THE STRUCTURE AND GERMINATION; 

 BY WM. WILSON, ESQ. OF WARRINGTON. 



[All who have had occasion to examine the minute seeds of 

 the different species of Lemna, must confess that it is ex- 

 tremely difficult, if not impossible, to comprehend their 

 structure satisfactorily, and that germination alone can teach 

 us the true nature of the different parts. The fructification, 

 however, of any of the species may be deemed of rare occur- 

 rence. Few botanists have been privileged by seeing the 

 seeds, and still fewer have had the patience to watch and to 

 describe them when in a state of developement ; nor, when 

 this is done, can the description be rendered intelligible to 

 another without the aid of magnified figures. I have 

 myself figured and described the fructification of three of our 

 British species of Lemna in the new series of the Floi'a 

 Londinensis, but ignorant as I was of the germination of 

 all of them, I confess I could not hazard an opinion on the 

 nature of those parts which were brought to view by the 

 dissecting knife. Nor am I aware of the existence of any 

 representation of the germination of any Lemna except that 

 (of Lemna gibha) published by Dr. Gaertner, from the ob- 

 servations of Mr. Hartmann, and given in the Botanische 

 Zeitung for March 1824, No. 12. These, however, appear to 

 be very imperfect. At length my valued friend Mr. Wilson 

 communicated to me, both in 1827 and 1828, the result of his 

 patient attention to the developement of the seeds of Lemna^ 

 and the result of these, together with his excellent figures, 

 are here given. — W. J. H.~\ 



As I considered (says Mr. Wilson,) that in a state of 

 nature the seeds always remained at the bottom of the water, 

 I did not attempt to immerse those which I preserved through 



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