VEGETABLE PHYSIOLOGY. 55 



of the apple, pear, or cherry, the gardener immediately dreads 

 the blossom falling off or proving abortive ; and experience 

 confirms the truth of this, for the powder of the anthers is spoiled ; 

 yet this accident oftener happens in the cherry than the apple or 

 pear ; for all the anthers of the cherry flowers discharge their 

 dust at once : but the case is not so in the others. Smoke is 

 also injurious, by drying up the moisture of the stigmas. 



6. Culture of Palm trees. That the cultivation of palm trees 

 were in use to pull off the spadices from the males, and suspend 

 them over the spathae of the females, is attested by Theophratus, 

 Pliny, Prosper, Alpinns, Kemper and many others. If this 

 operation happened to be neglected, the dates were sour and 

 destitute of nuts. Kemper adds this singular circumstance, that 

 the male spadix, after being thoroughly dried and kept till next 

 season, still retained its impregnating virtue. 



7. Nodding flowers. Since the male dust is generally of a 

 greater specific gravity than the air, in most plants that have the 

 pistil longer than the stamens, the all-wise Creator has made the 

 flowers nodding, that the powder may more easily reach the 

 stigma ; as may be seen in the common snow drop and violet. 

 Now it cannot be said that this happens merely from the weight 

 of the flower, for sometimes the fruit in the same plants, which is 

 ten times heavier than the flower, grows erect, as in the crown 

 imperial, fritillary and others. 



8. Sunk flowers. The stems of many plants grow under 

 water ; but a little before they blow, the flowers emerge or rise 

 above the surface of the water, when they blow, and swim till 

 they receive their impregnation and then sink again. 



9. Consideration of all sorts of flowers. Here a number of 

 particulars may be produced, but we shall confine ourselves to 

 those that are the most striking and applicable to the subject. 

 When the flowers of the male hemp are pulled off before those 

 of the female are fully expanded, the females do not produce 

 fertile seeds. But as a male flower is sometimes found upon a 

 female plant, this may be the reason why fertile seeds are some- 

 times produced even after this precaution has been observed. 

 The tulip affords another experiment of the same purpose, Cut 



