14.what convinnced Geibert that the substance was Marburg?

From the text:

"He didn't know if this thing was Marburg, but it sure as hell looked like a filovirus, a thread virus. Then an image came into his mind-an image of Peter Cardinal's liver cells exploded and flooded with snakes. He brought the image into mental focus and compared it with what he saw on the screen. He knew exactly what the Cardinal strain looked like because he had memorized its curlicues and Cheerio shapes."