7(1 



KN(»\VIJ.l)(jj:. 



l-'l.lll!l'AHV, 191. 



On the Kiiiss. leadinits 



SiinsliiiK; was in ilcfect in all ilislricls excopt Scotland. K., 

 wliiTc it was normal, with a daily iiicitn of 1 ■ 1 hf>uis. The 

 snniiii-st stations wiTr Maichmont, Cot-klc I'arU and 

 W'fvinoiilh. each with a daily average of 1-5 hours, but at 

 several stations the sunshine record for the week was nil. At 

 Westminster the daily average was 0-4 hours (5%). 



The temperature of the sea water was very Kenerally above 

 the average, and the means varied from 42°'0 at Hurninonth 

 to 50" -1 at Salcombe. 



The week ended January 13th was luisettled. with much 

 snow and sleet in the more northern parts of the country. 



Temperature was lower than of late, but was still ,-ibovc the 

 average of twenty-five years, except in fuiKland. N.Ii.. where 

 it was normal. The highest of the maxima did not exceed 

 54 , which was reported at a number of stations in difTercnt 

 parts of the country, including stations as far north as 

 StrathpcfTer. 



Frost was experienced in all districts except the English 

 Channel. In Scotland, R.. minima of 14" were reported 

 at West Linton, and 13" at Balmoral. 

 still lower were observed, 

 down to 10^ at Balmoral, 12" 

 at Buxton and 15" at' 

 Gl.isgow, and Newton Rigg. 



Rainfall was below the 

 average in Scotland, N., 

 England, S.E..and the I'nglish 

 Channel, but was above it 

 elsewhere. In Ireland the 

 total for the week was more 

 than double the usual amount. 

 There was heavy snow in Scot- 

 land on Monday; at Crieff it 

 was 10 inches deep, and at 

 Cratheswhen melted it yielded 

 1 ■ 78 inches of rain. 



Sunshine was deficient in \ ^^ r r r- Figure 71 



the Eastern districts, but was C. PeHihecbof ilie 



in excess in most of the Western districts. The daily average 

 for the district varied from 0-8 hours (10%) in the Midlands 

 and England, S.E., to 1-8 hours (23%) in Ireland, S. Dublin 

 was the sunniest station, with a daily average of 2-1 hours 

 (28%). .'^t Westminster the average was 0-6 hours (8%). 



The temperature of the sea water was above the average 

 at most places. The mean values varied from 40-2 at 

 Scarborough to 49 -"O at Scilly. 



MICROSCOPY. 



conducted xvith the assistance of the fotlowin^ 

 iiiicroscopists : — 

 Arthur C. Bankield. Arthur Eari./ind, F.R.M.S. 



The Rev. E. W. Hi.wri.i. Richard T. Lewis, F.R.M.S. 



Iamrs Burton. Chas F. Rousselet, F.R.M.S 



Chari.rs H. CAfFv.v. a I.ScoiRiiKiD, F.R.M.S. 



C. D. .Soak, F.L.S., F.R.M.S. 



THE SELBORNE SOCIETY'S CONVERSAZIONE.— 

 The number of microscopes shown at the .-\nnual Conversa- 

 ziones of the Sclborne Society is larger, perhaps, than at anv 

 other meeting nowadays in London. The next displav will 

 be on February 16th. in the offices of the Civil Service 

 Commission, Burlington Gardens, New Bond Street, W., and 

 any iiiicroscopists who would like to exhibit are requested to 

 communicate with the Secretary of the Selborne Society, at 

 42. Bloomsbury Square, W.C. 



SOOTY FUNGUS ON LEAVES AND ORANGES.— 

 It must often have been noticed that towards autumn the 

 upper sides of the leaves of many trees and shrubs become 

 covered with a soot-likc deposit. No doubt this is usuallv 

 looked upon as merely dirt and dust which has collected on them 

 during the summer. The commoner (jualities of oranges fre- 

 quently show the same thing, it being particularly evident near 

 the place to which the flower was attached. Of course there 

 is some dirt present in each case, but the appearance is generally 

 largely due to a fungus growing upon the surface. If the 

 leaf is .illowed to dry slightly, the coating may be detached 

 in flakes by carefully inserting the point of a knife under it. 

 Some of the thinnest pieces should be soaked in spirit and 



M>c 



of Ca/:„ 



water, to which a little glycerine may be added after 

 some hours. On examination under the microscnpe it 

 will be found that the object has the appearance repre- 

 sented in Figure 71, A. It is the mycelium of a fungus not 

 parasitic on the leaf, but obtaining its nourishment from 

 honeydew secreted by the green flies (aphides) so plentiful in 

 some seasons, and which falls on the upper surface of the 

 leaves of the lower branches. There is very little information 

 on the subject accessible to the ordinary microscopist, but the 

 fungus is mentioned and a figure given in Dr. M. C. Cooke's 

 "Fungoid Pests of Cultivated Plants." as Fuinago vagans 

 (Pers). He says: — "This black mould is familiar enough, as 

 it occurs on the foliage of numerous trees in this countr\', and 

 especially such as are subject to honeydew. It forms black 

 patches on the leaves to such an extent as to form a crust ; 

 but in this condition it is simply an imperfect fungus, and may 

 develop into a species of Capnodiitm or Meliola, as the case 

 may be." The specimens occurring on the orange may 

 be treated in the same manner as the others, and it is usually 

 e.mv tn nht.iin ll:il,i>; siirticifntlv large and thin for convenient 

 examination if the fruit is some- 

 what shrivelled. Such a flake is 

 represented in Figure 7 1 . B. It 

 will be noticed that the mycel- 

 ium difters from that of the 

 /•'ji;H<7j5o.beinglessmoniliform 

 and more filamentous in char- 

 acter, though there is much 

 \ariety in various examples of 

 both. In some cases a more 

 advanced stage is present and 

 perithecia may be found in con- 

 siderable numbers. (Figure 

 71. C.I These areerect bodies, 

 slightly thicker in the middle, 

 almost like narrow tall bottles 

 sometimes branched, compos- 

 ed of threads of mycelium 

 arranged side by side frequenth' with a spiral twist which is only 

 evident under a high power. .At the top the threads are separated 

 and form a fringe round the mouth i fimbriated), while others 

 spring from the sides and base forming a kind of imder.growth, 

 among which the perithecia are situated. These filaments are 

 much more thread-like than those composing the body of the 

 plant, the cells are longer, lighter in colour, with the divisions 

 between them far less distinct. Dr. Cooke says "genuine 

 spon'dia have never been found " but " minute sporules 

 or conidia have been met with." These latter are 

 plentiful near the specimens represented at Figure C, 

 but are too small to be visible under the same magnifica- 

 tion. The fungus also occurs on the leaves of orange 

 and lemon frees in Europe, the I'nited States, and 

 •Australia, frequently in sufficient amount to cause much 

 damage. When present on the upper surface it must prevent 

 the proper action of light on the chlorophyll, and when on 

 both sides, as it is sometimes in the mango ^Mangi/eiti 

 indica). it clogs the stomata and checks transpiration in 

 addition. There is considerable uncertainty as to the life- 

 history, and consc(|uently correct classification of the varieties, 

 but apparently when mycelium only is present and of the 

 character represented at .-V, the fungus is looked upon as a 

 Meliola. while when there are perithecia. with mycelium, as 

 at B and C. some species of Capiiodinni is indicated. What 

 is clear is, that all depend for their development upon the 

 presence of honeydew or the excrement of aphides, scale 

 insects, and so on, and that, though nut directly parasitic, they 

 cause much loss by hindering the vita! functions of the plants 

 on which they occur. The pretty little white four-winged 

 "snowy fly" iAleyrodcs'^. closely related to the scale 

 insects, which sometimes appe.irs in vast <|uantities on 

 cabbage plants as to constitute a pest, is often followed 

 by an attack of sooty fungus. The figures are drawn from 

 specimens mounted in glycerine jelly. That at A is from a 

 leaf of Hedge Maple X210: B and C .ire from an or.ange. 

 BX210,CX40. , ,,,.^.r„^._ 



