The bubonic form of the disease was a bacterium ( Yersinia pestis) spread by fleas from rats.
(The bubonic form of the disease; was; a bacterium ( Yersinia pestis) spread by fleas from rats) (a bacterium; spread; by fleas; from rats)
The bubonic form of the disease a bacterium
was spread
a bacterium ( Yersinia pestis) spread by fleas from rats
by fleas from rats