XC11 PROCEEDINGS OF THE ROYAL HORTICULTURAL SOCIETY. 



d'Or, and thence spread to the red varieties. Mr. Morris com- 

 pared its ravages with those of the Cemiostoma coffeellum, which 

 had destroyed plantations of coffee in Dominica. The best way 

 to destroy it was to pinch the leaves where the caterpillar was 

 burrowing underneath. 



Poa pratensis. — Dr. Masters showed specimens apparently of 

 this species, which was reported to be covered with a gummy 

 exudation. It did not appear to be present on the dried speci- 

 mens sent, but it was suggested it might have been honeydew. 

 Mr. Morris undertook to determine the species and to report 

 further upon it. 



Abies Xordmanniana. — Mr. Veitch sent a remarkable branch 

 of this species with a large burr, with spreading branches of a 

 yellowish hue. A discussion was raised as to the general cause 

 or causes of such structures, and whether they were hereditary 

 or could be propagated. The opinion entertained was that they 

 were originally due to the puncture of some insect, but the diffi- 

 culty lay in observing it at the time. Dr. Masters said he had 

 on one occasion noticed a number of seedlings of Fir trees having 

 such abnormal growths on the Simplon. It was proposed to 

 subject the specimen to microscopic examination, and to test the 

 powers of propagation. Varieties of Clanbrasilian Firs are known 

 to be readily propagated which have thus originated. 



Urtica dioica, monoecious. — Mr. Henslow exhibited specimens 

 of the female plants of the common Stinging Nettle with male 

 flowers at the extremities only of the female branches of the 

 panicles, corroborating the generally received view that the 

 occurrence of male organs is correlated with a reduced vigour. 



