24 THE TREES AND SHRUBS [LECT. 



and placing them over the cultivated ones, in order 

 to cause them to ripen their fruit sooner, an effect 

 in this instance merely due to the multitude of 

 insects of the cynips tribe, which were thus brought 

 into contact with the fruit of the cultivated variety, 

 and which pierce with their little proboscides the 

 membrane which incloses the seeds, thus by their 

 stimulus causing them to ripen sooner, so as to 

 allow time for a second crop. 



Accordingly, in this case the same effect may be 

 brought about by simply puncturing the figs with 

 a sharp instrument, and introducing a drop of oil 

 into the puncture to keep it open. 



This process, therefore, bears no real analogy to 

 the influence of the pollen upon the stigma of 

 a flower ; so that it would appear that Herodotus 

 had a very vague notion of the nature of this latter 

 operation. 



Neither does Pliny appear to have advanced 

 beyond the knowledge possessed by the writers 

 already quoted ; for although he states, that natu- 

 ralists admit a distinction of sex, not only in trees, 

 but in herbs, and in all plants whatsoever, yet in 

 proof of this position he only quotes the case of 

 the Date-palm, respecting which he offers a de- 

 scription of the same nature as that given us by 

 Theophrastus, although one couched in more po- 

 etical phraseology. 



Thus he says u , "that in a forest of natural 

 growth the female trees will remain barren if 



" Lib. xiii. 7. 



