CHAP. V. FUNCTION OF REPRODUCTION. 25.9 



effects take place once only for each plant, and it seems 

 most likely that they are the result of some chemical 

 action, rather than of any physiological property. 



SECOND PERIOD OF REPRODUCTION. 



(255.) Fertilization, Great progress has been made 

 within the last few years towards attaining an accurate 

 knowledge of the process by which the fertility of the 

 seed is secured. It had been long ascertained, that the 

 action of the pollen was somehow essential to this pur- 

 pose, and that the effect was also produced through the 

 intervention of the stigma ; but the manner in which it 

 took place was not understood. Even the ancients had 

 obtained some vague notions on the subject, although 

 their speculations regarding this as well as most other 

 minute details in natural science were replete with 

 error and absurdity. The general fact had forced itself 

 upon their attention in the cultivation of the date- 

 palm. As the blossoms of this tree are dioecious, the 

 distinction between those individuals which continued 

 barren and such as always bore fruit was of course 

 soon remarked ; and it was found to be necessary that 

 either some of the barren kinds should be cultivated 

 in the neighbourhood of those which bore fruit, or 

 else that bunches of their flowers should be suspended 

 near them, otherwise the fruit never attained per- 

 fection. Hence originated the custom of cultivating 

 only fertile plants, and of annually bringing bunches of 

 the sterile flowers from the wild trees a practice 

 which has prevailed from the earliest periods of history 

 to the present day in Egypt, and those countries of the 

 East where the date forms a most important article of 

 human food. When the French were in Egypt in 

 1800, the events of the war prevented the inhabitants 

 from procuring the blossoms of the sterile or male 

 plant (as it is considered) from the deserts, and none 

 of the cultivated plants in consequence bore any fruit. 

 (256.) Erroneous Theory of the Ancients. A prac- 

 s 2 



