C>90 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Mr. Douglas defines a Carnation and a Picotee, giving the properties of 

 each. The best varieties are mentioned, and full cultural details given. 



E. T. C. 



Pineapple Culture. By Albert H. Benson. Part III. (Qu. Agr. 

 Journ. xii. p. 340. May 1903). — This part, in continuation, contains 

 chapters on permanence of plantations, on replanting, on cultivation, on 

 shelter, and on growth of subsidiary crops between Pines. — M. C. C. 



Pineapple Culture, Soils in Florida. By H. Miller and H. H. Hume 



( U.S.A. Exp. Stn.Florida, Bull. 58 ; 9 plates). — Gives method of sampling, 

 chemical composition, requisites of a good Pineapple soil, descriptions 

 of localities, and characteristic wild vegetation. — E. A. B. 



Pineapples, Cultivation of. By C. E. Smith {Bull. Dep. Agr. 

 Jam. vol. ix. pt. 11, p. 161). — The author discusses the nature and 

 analyses of the sorts, propagation, gathering, insects and diseases, and 

 the varieties cultivated. — 67. H. 



Pine Beetle, The (Gard, Mag. No. 2598, p. 548; 15/8/03).— A 

 descriptive life-history of this destructive insect (Hylesinus piniperda), 

 which causes so much damage to coniferous woods and plantations. 



W. G. 



Pine : Bluing: and Red-rot of the Western Yellow Pine. By 



Hermann von Schrenk (U.S.A. Dep. Agr. Bur. PI. Lid. Bull. 36, 

 May 1903, 14 plates). — The investigations detailed were undertaken to 

 determine — 



(1) The cause of the blue colour in the dead wood of the Western 

 Yellow Pine (Pinus ponderosa), and the effect of the colouring on the 

 value of the wood. 



(2) The reason for the subsequent decay of the wood, the rate of 

 decay, and whether the decay could be prevented. 



(3) Whether it would be possible to use the dead wood before it 

 decayed ; first, to reduce the fire danger ; second, to prevent the decay 

 and thereby save an immense quantity of timber. 



It was found that the physiological changes were intimately connected 

 with the attacks of the Pine -bark beetle (De?idroctomis ponderosce), which 

 enter the bark in July, August, and September. The first signs of disease 

 noticeable in the affected tree are visible in the spring following the 

 a tiack of the beetle. Very soon after the attack of the bark beetle the 

 wood of the Pine turns blue. The colour is at first faint, but soon 

 becomes deeper. After a certain period the whole sap wood will have a 

 beautiful light blue-grey colour. The wood which adjoins the inner line 

 of the blue wood is of a brilliant yellow colour, which contrasts sharply 

 with the blue outside and the straw-yellow of the heartwood. The blue 

 colour develops very rapidly when once the tree is attacked. As the 

 cambium and bark cells lose water they shrivel and break from one another, 

 so that in a few months the bark breaks away from the wood. Numerous 

 white strands of fungus mycelium make their appearance after six months 

 or more. The blue wood differs very little from the sound wood in 



