SPREADING OF DISEASE AND EPIDEMICS. 147 



officially estimated at over i^2 0,000,000 sterling. 

 Need more be said ? Even allowing for consider- 

 able exaggerations in such estimates it is clear that 

 the damage to crops in any country soon amounts 

 to sums which even at low rates of interest would 

 easily yield incomes capable of supporting the 

 best equipped laboratories and staffs for investiga- 

 tions directed to the explanation of the phenomena 

 in detail, the sole basis on which intelligent pre- 

 ventive and therapeutic measures can be based. 

 But it is far from likely that the estimates are 

 exaggerated. The planting and agricultural com- 

 munities are as a rule opposed to the publication 

 of statistics or at least have been so in various 

 countries and at different times and if we knew 

 the damage done to all crops even in our own 

 Empire, the results would probably astonish us far 

 more than the above figures have done. 



Notes to Chapter XV. 



On the dissemination of fungi, the reader will find 

 P'ulton, " Dispersal of the Spores of Fungi by the Agency 

 of Insects," Ann. Hot., Vol. III., 1889, p. 207, and Sturgis, 

 " On Some Aspects of Vegetable Pathology and the Con- 

 ditions which Influence the Dissemination of Plant Diseases," 

 Botanical Gazette, Vol. XXV., 1898, p. 187, both useful 

 papers. Further information will be found in Zopf, Die 

 Pilze, Breslau, 1890, pp. 79-95 and 228, and Wagner, 

 " Ueber die Verbreitung der Pilze durch Schnecken," in 

 Zeitschr. f. Pflarizen Krankh., 1896, p. 144. The estimates 

 as to losses due to epidemics are taken from Watt, 

 Agricultural Ledger, Calcutta, 1895, p. 71 ; Balfour, The 

 Agricultural Pests of India, London, 1887, pp. 13-15; 



