Carrot samples containing ethylene oxide (EO), tetrahydrofuran (THF), and their hydrates were studied. It was found that: (1) the microscopic appearance of carrot tissue was not altered appreciably by EO or THF (no detectable hydrate crystals), (2) slow formation of EO hydrate (Type I) and THF hydrate (Type II) resulted in extracellular crystalline areas which were large and few in number, and their presence was associated with severe shrinkage and distortion of adjacent tissue (this behavior is similar to that observed during conventional slow freezing of carrot tissue), and (3) crystalline masses of EO hydrate in carrot tissue tended to increase in size and become less numerous as the rate of formation was decreased and the growth period was increased. These results differed from those obtained previously with animal tissue. EO (no detectable hydrate crystals) was much less detrimental to the microscopic appearance of carrot tissue than it was to the microscopic appearance of beef muscle (BM) or rat liver (RL). Furthermore, slow formation of EO hydrate resulted in extracellular crystalline areas which were larger and less numerous in carrot tissue than in BM, or RL, and this in turn resulted in cell shrinkage which was less uniform and more severe (adjacent to crystalline areas) in carrot tissue than in BM or RL.