THE BLOSSOMING OF OUE HAEDY CULTIVATED FRUITS. 551 



The aTerage length of time in flower is nineteen days (see Table E), 

 I: being in full bloom between the seventh and eighth days after com- 

 mencing to flower. A single individual flower is about six days between 

 the opening and the falling of the petals. The honey glands of the plum 

 are situated at the bases of the petals near their place of insertion on 

 the receptacle. Having but a single carpel, there is only one stigma. 

 In plums the anthers and stigma mature simultaneously.* 



The pollens of plum, cherry, apple, pear, strawberry, and rasp- 

 berry are very similar and of much the same size (figs. 164, 165). In 

 shape they resemble, when dry, a grain of wheat or date stone, but are 

 transparent and, of course, minute, their surface is almost smooth, 

 unlike the pollen grains of many other plants which often have spiny 

 outgrowths or irregularities which must assist their adherence to the 

 hairs on the bodies of insects. 



Mr. W. 0. Backhouse, of the John-Innes Horticultural Institu- 

 tion, Merton, Surrey, informs me that from his observations this year he 

 concludes the different vaHeties of plums to^ be on the whole self-fertile ; 

 he finds hybrids, however, tend to be completely sterile, thus 'Elvers' 

 Early Prolific ' sets with its own pollen with the greatest difficulty, 

 only setting nine plums out of as many thousand flowers ; whereas * Vic- 

 toria ' is completely self-fertile, the fruit having to be thinned in the 

 covered branches. The * Histon Apricot ' plum, the blue bullace and 

 the sloe, are all self -fertile. 



The old * Greengage ' shows itself self -sterile, but when dusted with 

 pollen of ' Early Elvers ' the fruit had to be thinned; in like manner 

 the pollen of the greengage on the ' Early Bivers ' gave a good crop. 

 Mr. 0. Maetin, of the Toddington Nursery Company, tells me that 

 ' Eivers' Early Prolific ' and * Black Diamond,' when planted separately 

 in large blocks, fruit badly, and the outside trees of the plantations 

 produce more than those of the interior. 



Taking an average from about twenty records in different parts of 

 the country and in different years, the following gives the average 

 order of blossoming of plums — 



Early Blossoming Plums. 



1. Japanese Plums. 



2. ' Grand Duke." 



3. ' Damascene. ' 



4. ' Black Diamond. ' 



5. ' Prince of Wales.' 



6. ' Monarch. ' 



7. * Eivers' Early Prolific' 



8. * Greengage. ' 



9. * Victoria. ' 



10. * Drooper. ' 



11. * Persliore Egg Plum. 



Late Blossoming Plu^ns. 



12. ' Bradley's King of Damsons. ' 



13. ' Sultan.' 



14. ' Oullins Golden Gage.' 



15. ' Jefferson. ' 



16. ' Farleigh Damson.' 



17. ' Oox's Emperor.' 



18. ' Ooe's Golden Drop.' 



19. * Prune Damson.' 



20. ' White Bullace.' 



21. ' Pond's Seedling.' 



22. * Late Orleans.' 



23. ' Belle de Louvain.' 



* The Fertilisation of Flowers, by Hermann Miiller. 



