A series of phase-contrast micrographs of a growing hyphal tip of R. solani taken 30, 60, 90, and 150 seconds after adding broth to a slide culture. This hypha continued to grow and exhibited polarized organization complete with a Spitzenkörper (S) for more than 5 minutes (not shown) after adding broth. Most mitochondria (m) were arranged parallel to the long axis of the hypha. Scale bar = 10 µm.