 Using these methods, "Caenorhabditis briggsae" and "C. elegans" nematodes were found that displayed abnormalities in the intestines, such as extensive convolutions of the apical intestinal border.The lysate of infected nematodes was added to healthy nematodes, which led to infection.Since for the lysate a filter was used that only allows virus particles to penetrate, this suggested that a virus was the cause of the intestinal abnormalities.