SCIENTIFIC COMMITTEE, OCTOBER 9. 



Ixxxvii 



A2)ples and Wasps. — Rev. Professor G. Henslow sent some apple skins 

 left after wasps had consumed the whole of the cellular tissue, abandoning 

 the core and particles of grit which formed a layer at the bottom. After 

 falling from the tree the skins became the domiciles of earwigs. He 

 also sent the following note : — " It has occurred to me that the presence 

 of ' grit ' disclosed by the wasps not being able to eat it (but undiscover- 

 able to us human beings, being too small) proves the last differentiation 

 between apples and pears to go ! I take it that ' grit ' is the degraded 

 state of an original stone fruit, the cores being the internal lining only 

 of the carpels. In a pear which has decayed the grit is clustered round 

 the five carpels, resembling that of other stone fruits ; but in apples it 

 has degraded so much further that only wasps can discover it ! " The 

 members of the Committee agreed with Dr. Masters who wrote : — " This is 

 a most ingenious idea ; but as the ' grit ' or mechanical tissue in a pear 

 is not confined to the neighbourhood of the carpels, but diffused in the 

 parenchyma, and especially beneath the epidermis, I cannot quite see how 

 it can be phylogenetically connected with the stone. The ' grit ' is an 

 integral portion of the fruit branch, not of the carpels." 



Scientific Committee, Octobek 9, 1906. 

 Dr. M. T. Masters, F.R.S., in the Chair, and nine members present. 



The late Professor Marshall Ward. — The following letter from Mrs. 

 Ward to the Chairman was read, and ordered to be inscribed on the 

 minutes : — " Will you kindly convey to the members of the Scientific 

 Committee of the Royal Horticultural Society the gratitude of myself and 

 my children for their kind sympathy and appreciation ? Such an honour 

 truly reflects the esteem in which my dear husband was held by his 

 colleagues, and we greatly prize the expression of it from your Society. 

 Permit me also to convey our thanks to you personally as Chairman." 



Blisters on Pear Leaves. — Mr. G. S. Saunders, F.L.S., reported that 

 the blisters on the pear leaves from Ulverston were the work of the 

 caterpillars of a small moth, one of the Tineince, which burrows between 

 the skins of the leaves, feeding on the parenchyma of the leaf. The 

 insect pupates in the soil. Removing the surface soil to the depth of 

 2 inches and burning or burying it deeply would probably prevent the 

 tree from being attacked again next year. If the tree is infested next 

 season, the affected leaves should be picked off as soon as the attack is 

 noticed — spraying would not be of any use. 



Imperfectly formed Acorns. — Mr. Saunders showed some acorns in 

 which the growth had evidently been arrested at an early stage. They 

 ivere from Quercus rubra. No member present knew whether the species 

 produced perfect fruit in this country, but it was thought that the arrest 

 of growth was due to uncongenial climatal conditions. 



Intoxication of Bees. — Mr. Saunders also showed some bees, received 

 from a correspondent, which had become stupefied while searching for 

 nectar in the flowers of Kniphofia. They had been unable to make their 

 way out of the tube of the flower, and so had perished. Other bees and 

 wasps had obtained the nectar through holes at the base of the floral tube, 



