Abstract
It has long been the Virologist’s dream to discover an easy and simple means for the cultivation of the poliomyelitis virus in vitro. Research was hindered for many years because the virus seemingly could not be adapted to any experimental animal other than the monkey. The monkey is not a suitable experimental animal for the average research worker because the care of the animals requires specially trained personnel and also because rather extensive and costly facilities are required for the maintenance of a monkey laboratory. | A big step forward was made in 1939 when Armstrong reported the successful passage of a fresh human strain of poliomyelitis (Lansing strain) from the monkey to Eastern cotton rats. He soon afterward further transmitted the disease to white mice. A smaller and more economical animal was now available to the Virologist. However, the maintenance of the virus was still able to be accomplished only by continued passage from one experimental animal to the next. Thus a more desirable experimental animal had been found but the means for maintaining the virus had not been improved. Recently it has been found that the virus may be successfully cultivated in certain types of tissue culture and this affords, to date, the most practical and suitable means for propagation of the virus.