in organic and inorganic Bodies, . 165 



bers, and in evident motion, along with a few of the larger 

 particles, whose motions were much less manifest, and in some 

 cases not observable*. 



In this stage of the investigation having found, as I be- 

 lieved, a peculiar character in the motions of the particles of 

 pollen in water, it occurred to me to appeal to this peculiarity 

 as a test in certain families of Cryptogamous plants, namely 

 Mosses, and the genus Equisetum, in which the existence of 

 sexual organs had not been universally admitted. 



In the supposed stamina of both these families, namely, in 

 the cylindrical antherae or pollen of Mosses, and on the sur- 

 face of the four spathulate bodies surrounding the naked 

 ovulum, as it may be considered, of Equisetum, I found mi- 

 nute spherical particles, apparently of the same size with the 

 molecule described in Onagrarice, and having equally vivid 

 motion on immersion in water ; and this motion was still ob- 

 servable in specimens both of Mosses and of Equiseta, which 

 had been dried upwards of one hundred years. 



The very unexpected fact of seeming vitality retained by 

 these minute particles so long after the death of the plant, 

 would not perhaps have materially lessened my confidence in 

 the supposed peculiarity. But I at the same time observed, 

 that on bruising the ovula or seeds of Equisetum, which at 

 first happened accidentally, I so greatly increased the number 

 of moving particles, that the source of the added quantity 

 could not be doubted. I found also that on bruising first the 

 floral leaves of Mosses, and then all other parts of those plants, 

 that I readily obtained similar particles, not in equal quan- 

 tity indeed, but equally in motion. My supposed test of the 

 male organ was therefore necessarily abandoned. 



Reflecting on all the facts with which I had now become 

 acquainted, I was disposed to believe that the minute spherical 

 particles or Molecules of apparently uniform size, first seen in 

 the advanced state of the pollen of Onagrarice, and most other 

 Phaenogamous plants, — then in the antherae of Mosses and on 



* While this sheet was passing through the press I have examined the pol- 

 len of several flowers which have been immersed in weak spirit about eleven 

 months, particularly of Viola tricolor, Zizania aquatica, and Zea Mais; 

 and in all these plants the peculiar particles of the pollen, which are oval 

 or short oblong, though somewhat reduced in number, retain their form 

 perfectly, and exhibit evident motion, though I think not so vivid as in 

 those belonging to the living plant. In Viola tricolor, in which, as well as 

 in other species of the same natural section of the genus, the pollen has a 

 very remarkable form, the grain on immersion in nitric acid still dis- 

 charged its contents by its four angles, though with less force than in the 

 recent plant. 



the 



