Phytophthora infestans has three kinds of somatic nuclei: an oval shaped nucleus (approx. 3.1×2.7 μ) which stains diffusely except for a crescent shaped Feulgen positive “cap” which stains intensely; a “granular” nucleus whose contents are organized into a fairly constant number of stained bodies, and, a deeply staining “condensed” nucleus. The “capped” nucleus is thought to be “metabolic” or “resting” and the “granular” nucleus is thought to be dividing as it is most commonly found in hyphal tips. Attenuated forms of all three kinds of nuclei are found.