THE PEAR FLOWER. 



15 



Yery often the styles protrude from between the petals before the 

 latter open out; thus the early openiug of the petals favors eross- 

 polliuation, for the stigma is exposed to receive pollen from inse(5ts 

 some time before tlie pollen in its flower is set free. Further, the life 

 of the flower as an open blossom is longer. At Koehester in the sirring- 

 of 1892 many flowers opened by the time tlie petals were one-half their 

 full size. Three or four dry, sunny, and windy days occurring at 

 that time, favored the opening of the petals, but not their growth. 

 In wet weather the reverse of the above occurs. The stigma, instead 

 of being exposed by the opening of the petals long before the ripening 

 of the stamens, remains inclosed until the stamens have reached 

 maturity, or in some cases have actually discharged their pollen. 

 Sucli a case occurred in the si)ring of 1892 in Virginia, where cloudy 

 and rainy weather x^ievailed during the blossoming time. 



These two cases, however, may be regarded as extreme. The normal 

 method is for the petals to expand when about two-thirds grown and 

 expose the stigma fully matured. It remains in this condition about 

 four or five days. In the course of from one to four hours after the petals 

 open the first stamen sheds its i^ollen, and the others follow in suc- 

 cession, so that from three to six will have opened by night. Each 

 stamen is curved inward toward the center of the flower in the bud, 

 and only straightens out when its anther discharges its pollen. The 

 anther does not burst suddenly and scatter the pollen, but a tiny rent 

 appears, which takes several minutes to open fully. Grenerally, but 

 not always, the two anther cells open at the same time. The walls of 

 the anther cells curl back after they have rui)tured, and by drying- 

 become comparatively inconspicuous. The rupture of the anthers 

 occurs along a previously determined line and the opening is brought 

 about by a special kind of tissue composing the walls. 



Three distinct kinds of anthers are to be seen on the flowers, 

 (1) those which have not oi)ened, (2)- rui)tured anthers which retain 

 their mass of yellow pollen, and (3) rux3tured anthers which 

 have been stripped of x)ollen by insects. Where bees are scarce or 

 when cold or cloudy weather keeps them from working, ruptured anthers 

 with pollen attached are abundant throughout the day. Even when 

 bees are numerous and warm weather favors their working there is 

 always an abundance of loose pollen up to about 10 a. ra., by which 

 time the bees will have stripped it from most of the flowers. During 

 the second day that a flower is open the greater part of the anthers 

 discharge their pollen. If any are left they open out the third day. 

 Cold or wet weather will jDrolong this time. The pollen is not dry and 

 dust-like at first, but is inclined to hold together, and if not removed 

 by bees remains attached to the anther for a day or more. The large 

 numbers of ruptured anthers with pollen to be found in the morning 

 may possibly be due to the fact that they have opened during the night, 

 when there are no bees at work. It is more probable, however, that 



