216 A MANUAL OF BACTERIOLOGY 



favour its development. Professor C. Tommasi- 

 Crudeli 1 states that the following conditions are 

 necessary for the Bacillus malaria to produce spores : 

 (a) ' Une temperature de 20 degres centigrades 

 environ ; (b) un degre" mode're d'humidite* perman- 

 ente; (c) 1'action directe de 1'oxygene de Fair sur 

 toutes les parties de la masse [that is, of the soil]. 

 II suffit que Tune de ces trois conditions fasse 

 deTaut, pour que le deVeloppement des sporules, et 

 la multiplication du ferment malarique, soient ar- 

 retes.' In marshy districts, the larger the amount of 

 organic matter present in a soil, the greater will be 

 the prevalence of malaria. The disease is more 

 prevalent the lower the level of the country, although 

 in Central Africa a height of 2500 feet is not free 

 from it. Both air and water may convey the dis- 

 ease, and there is little doubt that it finds an entrance 

 into the system by means of air, potable water, and 

 food. 



Bacillus malarice (2 to 7 //. long) gives rise to 

 leptothrix filaments, and produces spores either at 

 the ends or in the centre of the cell (Fig. 38, 18). 

 This bacillus was found in the blood of malarial 

 patients by Klebs and Tommasi-Crudeli, 2 and they 

 also found it in the spleen, medulla, lymphatic 

 glands, and venous blood of persons dead of malaria. 

 On gelatine B. malarice gives rise to a well-developed 

 growth, and when a drop of the culture is inoculated 



1 La Malaria de Rome et VAncien Drainage des Collines 

 Romaines (Paris), 1881 ; and Atti ddla R. Accademia dei Lincei, 

 1879. 



2 Atti ddla R. Accademia dei Lincei, 1879, 1880, and 1881 ; 

 and Archivfur Experimental Pathologie, 1879. 



