346 



NA TURE 



[February 13, 1908 



Apart from the research work connected with the 

 college, we gather that an increasing use is made of 

 this institute " as an advisory centre on matters re- 

 lating to agriculture and horticulture, so much so 

 that in future years each department of the work of 

 the college will have its special journal." In the 

 section devoted to the report of the economic zoologist, 

 Mr F. V. Theobald, no less than 119 pests are dealt 

 with, chiefly under the following heads : — those in- 

 jurious to man's domestic animals, to fruit trees, 

 ro pulse, hops, and vegetables, flowers, forest trees, 

 food-stuffs, and those causing annoyance to man ; 

 and beside these are some replies to Extra-British 

 inquiries. One of the more interesting portions, 

 issued from this department, is that dealing with 

 the habits of the woolly aphis (Schizoneiira lanigera). 

 The author has conclusively proved that the damage 

 done by the root form of this pest is much more 

 severe in this country than has been generally sup- 

 posed. In view of this, Mr. Theobald attributes the 

 failures in treatment because we have hitherto ignored 

 the presence of the migrating ground form. An in- 



energy in turning his extensive knowledge of fungi 

 to practical account for the benefit of fruit growers 

 in this country. The detection of the outbreaks of 

 American gooseberry mildew {Sphaerotheca mors- 

 tivae) (Figs, i and 2) by him was followed by an ener- 

 getic and tactful campaign to bring about the stamp- 

 ing out of the disease, and his efforts have been re- 

 warded by the introduction of the Bill dealing with 

 fungus attacks into the House of Lords. The Board 

 of Agriculture and Fisheries has now made an order 

 which may be cited as the Gloucestershire and Wor- 

 cestershire (Gooseberry Mildew) Order of 1907. It 

 came into operation on July 22. This constitutes 

 the first legislative measure against fungus diseases 

 put into force in this country. The fungoid disease 

 of the gooseberry was discovered in the winter of 

 1906 in some commercial plantations in Worcester- 

 shire and Gloucestershire, but it had previously been 

 introduced into Ireland on disease'd stock imported 

 from America. It is during the so-called " summer 

 stage " that this mildew spreads most rapidly, as at 

 this period the chains of Conidia are produced in 

 continuous succession day and night. 

 We gather that the cherry orchards in 

 certain portions of Kent are still 

 seriously affected by the fungus Gno- 

 moniu erythrostoma, which depends 

 " absolutely for the continuance of its 

 existence on fresh infection taking 

 place in spring by means of the spores 

 scattered from the fruit-conceptacles of 

 the fungus on the dead leaves hanging 

 on the tree." . R. N. 



THE GEOLOGY OF 



TRANSVAAL.' 



THE 



Gooseberrj"- 



jection of carbon bisulphide is recommended for the 

 terrestrial, and a caustic alkali wash for the arboreal 

 form. In a short note on the habits of the house fly 

 {Miisca domestica), this insect is said to "have bred 

 largely in rotting cow-dung mixed with vegetable 

 matter." We may add, however, that in one of our 

 largest cities, stable midden-^ and ash-pits form the 

 chief breeding places for this fly ; anything in the 

 form of decayed vegetable: matter, such as the dung 

 of pet animals, vegetables, or even paper, provides 

 food for the larvae, and more especially so where heat 

 is engendered. 



Messrs. H. E. Annett, F. V. Darbishire, and E. 

 Russell furnish the report from the analytical 

 laboratory, in which it is stated that 250 samples ot 

 various substances were sent in for analysis - during 

 the past year. A detailed account is given of some 

 of these ; others are dealt with briefly. They are 

 treated under the following heads :— Manures, feed- 

 ing-stuffs, poisons, milks-, waters and soils. 



The reports from the botanical department are con- 

 tributed by the four members of the staff. Mr. E. S. 

 Salmon, the mycologist, has given evidence of his 

 NO. 1998, VOL. 77] 



nPHE most interesting features of 

 -'■ the report of the Transvaal Geo- 

 logical Survey for the year 1906 are 

 the excellent pieces of detailed mapping 

 of tlie rocks of the Transvaal System, 

 in the Lydenburg district, between 

 L\dt'nburg and Belvedere, bv Mr. .■\. L. 

 Hall, and in the area immediately east 

 of the Crocodile River and south of the 

 Rooiberg by Mr. W. s\. Humphrey. 

 These two districts form parts of the 

 same great synclinal trough ; but while 

 the Lydenburg district is at the eastern 

 end of the trough, and is as remarkable for the 

 simplicity of its geological structure as it is 

 famous for the grandeur of its scenery, the area 

 mapped by Mr. Humphrey lies 200 miles to 

 the west and nearer the centre of the trough, 

 and is characterised bv an exceptionally complicated 

 structure. Surrounded by the much later Red Granite 

 formation, the isolated inliers of the Transvaal 

 System in the latter area owe their position to faulting 

 and folding on a large scale, an adequate explanation 

 of which can only be forthcoming when the area to 

 the west is mapped in detail. 



In both districts tlie three members of the Trans- 

 vaal System are developed — narhely, the Pretoria 

 Series, the Dolomite, and the Black Reef .Series. The 

 quartzites of the Black Reef .Series, which form the 

 lowest division, attain to an unusual development in 

 the northern part of the Lydenburg district, where 

 they form the main portion of the great escarpment 

 of the Drackensberg, and play a considerable rSle in 

 determining the wild character of the scenery. 



1 Tran=;vaal Mines Department. Report of the Geological Survey for the 

 Year 1906. [Pi-etoria, 1907.) Price 7.^. 6(/. 



