736 Queries and Answers. 



Of tlic Otahrilcnn Arrow-root (Tacca jnnnalijida L.), ichnt Proportion 

 does the Fvcitid i/kldcd bear to the JVeig/it of Tubers from wliich it is derived? 

 and what is the Relation <f the Weight of Tubers to the superficial Quantity/ 

 of Soi/ producing that Weii-hl? — Your correspondent, Mr. Mathews of 

 Lima, has furnished (p. 58.5.) a most vahiable communication on the 

 fecuhi aflbrded by the roots of the Tucca pinnatlfida, and the mode by 

 whicli it is separated from tliem by tiie inliabitants of Otaheite. To this 

 information if he could furnisii a statement of the proportion of fecuhi 

 obtainable from any f^iven \veij;ht of the washed roots, and tlie probable 

 weight of roots obtainable as a crop from an acre or any other given 

 quantity of ground, he wouUl confer an obligation on such of your readers 

 as reside in countries adapted to the cultivation of this esculent. Its in- 

 troduction into our West Indian Islands, by increasing the amount of 

 human food produced within them, would [)erhaps be attended with much 

 advantage to the inhabitants, both as a source of domestic supply and of 

 profitable exportation ; and if any of your readers should possess a suf- 

 ficient share of [)hilanthro[)y to furnisii me (under a frank) with a few of 

 the seeds, it will afford me much pleasure to distribute them among my 

 correspondents in the West Indies, accoinpanietl by any information re- 

 specting their culture, &c., which the donor may feel disposed to transmit 

 to me along with them. — Wni. Ilanii/ton, AI.D. Oxford Place, Plj/niouth, 

 Oct. 15. 18.32, 



How can Plants of the Genus Citrus be prevented shedding their Leaves 

 and young Fruits ? — I should be much gratified if any cultivators of the 

 genus Citrus would inform me of a method to prevent the plants shedding 

 their leaves and fruit on being removed from a green-house to another 

 situation. Tliis last season I removed three large plants from a green- 

 house to a light airy room, of very similar temperature, ami the door of 

 which was almost constantly kept open, as was that of the green-house. 

 Notwithstanding this parity in the condition of the plants, they lost many 

 of their leaves and all their small fruit. — I.J. Oct. 13. 1832." 



The Corolla of Calijstcgia scpium Brown closes in a different Manner from 

 that in which the Corolla of Ipomcv'^n ])urpurcn Lamarck closes : is there any 

 Difference of Structure to account for this ? — In my garilen, Calystfcgia 

 sepiiun and Ipomce^a purpurea are growing together, and are twining up 

 the same strings. I have watched them attentively in all their stages of 

 flowering, and have seen with surjirise the different manner in wliich the 

 corollas close w hen they begin to lade. Those of Calystcgia scjiium close 

 togetiier in longituilinal folds, while the edge of the corollas of Ipomoe^a 

 purpurea curls inwards upon tiie parts of fructification. Is there any dif- 

 ference in the structure of the corollas, to account for the difierence in tiie 

 manner of their withering V — John li. Howe. U'imborne, Sij)t. 15. 1832. 



7V/r fittest Soil for, and Manngement of. Auriculas in low Situations. — Sir, 

 I should feel grateful for plain <lirections as to soil and management 

 requisite for the Primula Auricula in low situations. In Vol. IV. p. 240. 

 you mention Mr. Clray's having written a judicious pajier on this subject; 

 but of his mode of treatment no mention is maile. It is something of 

 this kind that I am in want of, as I have Hogg's Treatise on Florist's Flowers. 

 I am. Sir, yours. — P. U\ 



On preserving Cape Heaths from ]\Iildew. — I should feel greatly obliged 

 to any cultivator of that most beautiful and interesting genus /-'rica, for an 

 explanation of the cause, and instructions for the prevention, of a sort of 

 mildew which sometimes attacks these plants in our green-houses and 

 frames. It fre(|uently destroys a whole set of [)lants in a very short time. 

 I fuul no account of it in the last edition of Sweet's Potanicnl Cultivator, 

 nor in M'Nali's Treatise on Cape Hiaths. I have been informed that 

 suflering water to be jioured over their tops will cause it ? I hope some 

 experienced cultivator will early advise me on this point. — R. iV. 



