Pleomorphism is understood to be a phenomenon that has to do with plant life. Specifically, a pleomorphic event has to do with the development of two or more structural forms during a life cycle. Here is some background on the discovery of pleomorphism, and some of the controversy surrounding the concept.
Pleomorphism was first discovered as an activity associated with the life cycle of some plants during the early years of the 20th century. Essentially, the basic idea of pleomorphism revolves around the performance of bacteria during the cycle. Bacteria is understood to have the ability to change its shape dramatically during the life cycle, as well as change or morph into a series of different forms that continue to shift in shape for the duration of the cycle. Among the proponents of pleomorphism was well known scientist Antoine Bechamp. The idea behind pleomorphism was that the concept would provide an effective answer to one of the major questions of the medical community, which was how to effectively isolate and identify bacteria, and as a result develop effective treatments.
While pleomorphism attracted a great deal of attention, there was also a large body of scientists who believed the concept was faulty. Some of the notable opponents to pleomorphism were such respected figures as Rudolf Virchow, Ferdinand Cohn, and Robert Koch. Many of the detractors chose to support the concept of monomorphism, which held that all forms of proteus more or less held its shape and only produced other protean cells that were of a similar shape. Over time, monomorphism became the dominant concept in scientific thinking, and continues to occupy that status today.
While the original concept of pleomorphism is not given a lot of attention today, the designation is sometimes applied in other ways. For example, certain types of viruses are sometimes said to exhibit tendencies that are similar to the process of pleomorphism. This is due to the fact that the virions that form the basis for many viruses are understood to demonstrate a number of different shapes. However, referring to this phenomenon as pleomorphism is not completely in line with the original theory. While it is true that successor virion cells may take on a slightly different shape than that of the parent, there is no indication that the parent itself will shift in form or appearance.
More appropriately, pleomorphism is associated with malignant neoplasms, which do tend to exhibit some ability to change in shape and size over time. In addition, the tumors that may develop from these neoplasms may also take on a variety of shapes and sizes as well.