SIXTH EXPERIMENT. 



The Datisca cannabina {Smooth-stalked Bastard Hemp) was raised from seed about ten 



years ago in my garden. 



It abounded in flowers, but these h^mgfeijiales, therefore proved abortive. 

 In order to obtain a jiiale plant I procured some seeds from Paris. 



These also grew well, but what vexed me was, they all ^voYQ.d females, and, therefore, 

 produced me also flowers without fruit. 



At length, in the year 1757, I procured other seeds. 

 Out of these some plants were males, and in the year 1758 flowered. 



These I removed into a border very remote from th^ females. 

 Therefore, when the male flowers Avere mature for shedding their Farina, I held a * paper 

 under them, and gently agitated the loose spike of flowers with my finger, until the whole surface 

 was nearly covered with yellow Farina. 



I carried this to th^ female flowers, which were produced in another part of the garden, and 



sprinkled it over them. 



The result was, these female flowers alone ripened their fruits where I had dispersed the 

 Farina, and their seeds attained their due magnitude ; but in all the rest, being fertilized by no 

 Farina, there appeared not a vestige of any seeds.f 



SEVENTH EXPERIMENT. 



The Phcenix Dactylifera {Date-hearing Palm) a long time flowered at Berlin, but pro- 

 duced no fruit. 



* KoELREUTER, a famous experimental botanist, sent, from iiCarZsra/ie to Gleditsh, the farina of the male cham.erops humilis 

 by post, with which, by means of a camel's-hair brush, he impregnated a female plant in his garden, and, for the first time, obtained ripe 

 seeds, from which he raised young plants. 



f Sometimes, however, under such circumstances, the seeds arrive at their due magnitude, but, as was long since observed, are 



barren. 



" Mr. Jacob Bobart, overseer of the Physic Garden at Oxford, about thirty-eight years ago, which was before the doctrine of the different 

 sexes of plants was well understood, herborising in the country, observed a plant of the Lychnis Sylvestris simplex, whose flowers, though 

 they had stamina, yet there were no apices; and finding this not in one, but in all the flowers upon the same plant, this made him imagine it 

 might be a new species, and therefore he marked the plant, and took care to have it preserved till the seeds were ripe ; and he at length pro- 

 cured them full hard and firm, and to outward appearance Remplis des germe (as Mr. GeofFroy has it). He failed not to sow them in his 

 o-arden next season in a proper place, but there was never a plant which sprung up. 



I had this account from the celebrated Dr. Sherard, at whose desire I have inserted it, and both of them being persons of such esteem, 

 and so good credit, I may venture to say it sets the opinion of the different sexes of plants upon another footing than it is received by most of 

 our modern authors; for this imports that it is not the nourishment of the gross substance of the seed itself, which is hereby meant, nor the 

 increase of the seed-vessel, which is thereby designed, for, as is observed, a hen can lay an egg without previous congress with the cock, and 

 this shall be the same for colour, taste, (when new-laid) smell, bigness, with another egg which has the tread (as they call it), i. e. that 

 has been fecundated by the Materies Seminalis Masculina ; but the difference appears when both are put under the hen to be hatched, the 

 one shall pullulate or chit, and the other shall become fetid and rot. 



The Lychnis Dioica {TVild Red Lychnis) being made by me the subject of experiment, gave additional confirmation of the Sexes 

 of Plants." Vide Blair on the Generation of Plants, in liis Botanical Essays. 



The learned Dr. Hope, late professor of botany in the university of Edinburgh, a strenuous advocate for the sexes of plants, made the 

 following experiment. He found of this Lychnis dioica two kinds, the white and the red ; and he was convinced (as are since this time Pro- 

 fessor Martyn and Mr. Curtis) that these are not varieties, but distinct species, and that the white never produces naturally red flowers. He 

 placed under the same bell the red and the white Lychnis Dioica, the one a male and the other a female plant, and the bell terminated in a 

 tube for the admission of air, but filled with moss, to hinder the access of any other farina; and from this white female Lychnis he obtained 

 seeds, which produced him some red Lychnises. Vide Note * in the description of the Carnation to our Picturesque Plate, where the doctrine 

 of the Sexes of Plants is further confirmed by observations on that flower. 



Some 



