154 A MANUAL OF BACTERIOLOGY 



bees by feeding them with material containing these 

 bacilli. 



This microbe is best stained with methyl violet ; 

 but the spores resemble the spores of other microbes 

 in not taking on the stain. Fig. 37 represents the 

 passage of a spore into the bacillus condition, and 

 vice versd. 



Bacillus of Grouse Disease. Dr. Klein 1 has re- 

 cently proved the microbian nature of grouse disease. 

 The disease, which is infectious, is caused by a 

 bacillus measuring T6 x 0'6 //,. It grows well on 

 agar-agar at 36 to 37 C. 2 ; also on nutrient gelatine 

 and in alkaline bouillon. Klein proved the patho- 

 genic nature of the microbe by a series of inocula- 

 tion experiments. The bacillus is readily stained 

 by Weigert's method. 



Bacillus suUilis. The hay-fever microbe was 

 originally isolated from an infusion of hay. It 

 measures 6 x 2 //,, and has slightly rounded ends. 

 This bacillus occurs singly, in short chains, in lep- 

 tothrix filaments, and in zooglcea. It forms oval 

 spores (I'2x0'6 //) ; but spore-formation occurs 

 only when there is an ample supply of air ; never- 

 theless it is independent of any deficiency of 

 nourishing material (Klein). The bacilli when 

 single possess one or two flagella (Fig. 33, 10). 

 ' The bacilli form a dense resistant pellicle on the 

 surface of the nourishing medium, and in this 

 copious spore-formation takes place. If shaken 



1 Gentralblatt fur Bakteriologie und Parastienkunde, Bd. vi. 

 pp. 36 and 593 ; Bd. vii. p. 82 ; and Bd. ix. p. 47. 



2 That is, in from two to four days. 



