 He quickly realized these glassy areas were the result of the destruction of the bacterial cells and was able to pick from some of these areas and transmit this from one staphylococci colony to another.Further experiments showed the agent could pass through porcelain filters and it required bacteria for growth.These observations show Twort had discovered most of the essential features of bacteriophages, although Twort seemed to favor the idea that the principle was not a separate form of life, but an enzyme which is secreted by the bacteria.