350 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Sobralia virginalis lilacina, Cogn. (Cogniaux in Diet. Icon. Orch. 

 Bobralia; pi. 3a; 2/1902). — A beautiful variety introduced from 

 Colombia by M. Patin for M. Peeters, of Brussels. Differs from the 

 type in having a delicate lilac tint around the front lobe of the lip. 



C. C. H. 



Soil, Natural Fertility of. By J. J. Willis (Gard. Mag. 

 No. 2516, p. 32; 18/1/1902). — The writer of this article discusses the 

 question of natural soil fertility from a scientific standpoint, and explains 

 clearly how soils in a primitive condition become gradually more fertile 

 by the influences of atmospheric changes, and by the decay of organic 

 compounds which combined with inorganic constituents render natural 

 soils fertile for the support of vegetation. — W. G. 



Solanum Xanti. By Sir J. D. Hooker (Bot Mag. tab. 7821).— 

 Nat. ord. Solanacece, tribe Solancce. Native of California. It is 

 remarkable for the extraordinary variability of the leaves. The flowers 

 are of a pale purple colour in an umbellate cyme. — G. H. 



Sonerilas, Floriferous. By F. Rehnelt (Die Gart. p. 325 ; 12/4 

 1902 ; with illustrations). — On the Continent these pretty stove plants 

 are at the present time in great favour. Formerly grown under hand- 

 lights in hothouses, far finer plants are now grown without these lights. 

 Specially recommended are Sonerila Hendersoni argentea, S. mar- 

 garitacea, S. oricntalis, and several hybrids. — G. B. 



Sphaerotheca mors-uvae (Schw.) or Gooseberry Mildew : Its 

 Occurrence and Distribution in Russia. By P. Hennings (Garten- 

 flora, p. 170; 1/3/1902). — This destructive Gooseberry parasite is 

 common in North America, and has been met with in Ireland. (See 

 Salmon, Journal R.H.S., 1900, pp. 139-142.) The author received 

 specimens from near Moscow and considers it indigenous in Russia. — J. P. 



Spinach. By E. D. S. (Journ. Hort. p. 162; Feb. 20, 1902).— 



Notes are given concerning this crop. In light dry soils Tetragonia 

 expansa, called New Zealand Spinach, makes a good substitute ; also Beta 

 viaritima, called Spinach Beet, may be gathered all the year round. A 

 bed of Chenopodium Bonus Henricus (' Good King Henry '), hardy and 

 perennial, is always useful for early gatherings. — C. W. D. 



Spiraea Millefolium. By Sir J. I). Hooker (Bot. Mag. tab. 7810).— 



Nat. ord. Rosacea, tribe Spirceece. Native of California. It is remark- 

 able for emitting an odour of creosote. It grows to 3 feet in height at 

 Kew, and flowered in the open air in 1901. The flowers have a white 

 corolla, i inch in diameter, being crowded in terminal panicles. — G. H. 



Spraying* for Horticultural Diseases in the United Statss 



(U.S.A. Hurt. Soc. Illinois, 1901, pp. 7, 191, 219, 385,387,390, 451, 

 486, &C, ; tabs., plates, etc.). — Quite a large amount of information on 

 this subject has been collected together in this volume as a result of 

 research and experiments of an extensive nature. Directions, formulas, 



