t 744 ] 



are to be recognised as Bacteria and not micrococci. If the 

 general appearance of a group of microbes is that of bits of 

 thread or cylindrical rods of different lengths, these are to be 

 identified as Bacilli. These may be straight bent or curved, 

 fine or fairly plump, of the same thickness throughout or 

 beaded or knot-like in appearance. When the bacilli are 

 serpentine (i.e., made up of small S's) they are to be recog- 

 nised as Vibrios', and when they are cork-screw shaped they 

 are called either spirilla or spirochaetae. If the cork- 

 screw shaped thread does not bend but remains straight while 

 moving it is called a spirillum, but if it is seen to bend as 

 most of them do when they are observed under the micros- 

 cope, it is called a spirochaetae. The common bacillus of 

 cholera is to be classed as a spirillum, representing part of 

 one turn only. 



1,288. Besides these simple forms, viz.) micrococcus, 

 bacterium, and bacillus (with its variations of vibrio, 

 spirillum, and spirochaetae), there ate complex forms under 

 each group. Where the micrococci usually occur in 

 pairs, they are called diplococci. The microbe of fowl- 

 cholera (guti) is a diplococcus. When micrococci occur in 

 chains they are called streptocoeci. When they occur in 

 groups of four they are called tetrads or tetra-coccus. Where 

 they occur in the form of cubes or square clusters, they are 

 called sarcinae. Where they occur in irregular masses, they 

 are called staphylococci \ and where they occur in large un- 

 interrupted masses in the form of slime or scum, they are 

 called zooglcea. The cocci in each case may be either simple 

 or flagillated or ciliated. Flagillated bacteria, micrococci and 

 bacilli, also spirilla, move very fast. The germs of typhoid 

 and of colic have cilia on their sides and hence they 

 look like centipedes or spiders under the microscope. Bac- 

 teria also occur singly or in pairs and they are also sometimes 

 flagillated. Bacterium termo, the ordinary germ of putrefac- 

 tion, usually occurs as a double spindle provided with flagella 



