450 APPLIED BACTERIOLOGY 



liquefying in the form of a circular, funnel-like tube, 

 the whole contents of the tube soon becoming liquid. The 

 liquefied gelatine is very turbid, it containing an abundant 

 deposit of a crimson colour. 



Agar-Agar. — Grows rapidly, producing a blood-like ex- 

 pansion, the growth being restricted to the surface. 



Potatoes. — Luxuriant growth of a beautiful crimson 

 colour, which afterwards develops a metallic lustre. 



Proteus Vulgaris. — This organism is found in putrefying 

 animal substances, sewage, water, etc. It forms slightly 

 bent bacilli about 0'6 /* broad and of variable length up to 

 3'8 /J, ; also gives rise to snake-like threads, resembling 

 plaits of hair. It has a great tendency to form involution 

 forms. The organism is very motile. Cultural characters : 



Gelatine Plates. — The colonies are yellowish-brown in 

 colour, with bristling edges, which afterwards throw out 

 irregular branches. In the depth characteristic zooglcea 

 forms are met with. 



Gelatine Tubes. — The gelatine is rapidly liquefied, when 

 the whole of the contents are liquid ; a whitish-gray cloud 

 is visible at the surface, while at the bottom collects an 

 abundant thick crumbly deposit. 



Agar-Agar. — A thin-spreading, moist, shining, grayish- 

 white expansion is formed. 



Potatoes. — A dirty-white smeary growth is formed. 



Proteus Mirabilis. — This organism is found in water, 

 putrefying animal substances, etc. It occurs in rods of 

 different lengths up to 2 or 4 /a long by 0-6 fi broad. It is 

 very motile, and readily gives rise to involution forms. 

 Cultural characters : 



Gelatine Plates. — The colonies form circular white ex- 

 pansions, which, under low powers, appear brownish and 



