The "unidentified" category (Table 13) refers to jellylike masses in the stomach or material in the intestine in which no scales, feathers, hair, or bones could be found. Most of the unidentifiable matter could be assumed to consist of remains of amphibians, since they leave no hard parts. If this assumption is correct, amphibians comprise about 40 per cent of the diet. Since intestinal contents were included, a volumetric analysis was not feasible. Therefore, the weight of each type of food item was estimated and the percentage by bulk calculated from it (Table 13). Pieces of dead leaves and small sticks constituted most of the plant material found and presumably were ingested secondarily because they adhered to the moist skin of the prey, especially to fish and amphibians. However, some plant materials probably are eaten because they have acquired the odor of the prey. One cottonmouth contained a _Hyla cinerea_, several leaves, and five sticks from 37 to 95 millimeters long and from 12 to 14 millimeters in diameter. Most reports in the literature state that gravid females do not feed, but four gravid females examined by me containing large, well-developed embryos also contained evidences of having recently fed. Two of them had scales of snakes in the stomach or intestine, one contained a six-inch _Lepomis_, and the other had hair in the intestine and the head and neck of an adult egret in the stomach. MORTALITY FACTORS Natural Enemies and Predators Published records of other animals preying on cottonmouths or killing them are few. Reptiles more often than other classes of vertebrates prey on the cottonmouth. McIlhenny (1935:44) reported on the scarcity of snakes in areas where alligators were present. Predation on cottonmouths by indigo snakes (_Drymarchon corais_) was reported by Conant (1958:153) and Lee (1964:32). Allen and Swindell (1948:6) obtained a photograph of a king-snake (_Lampropeltis getulus_) killing a cottonmouth but thought that moccasins are not eaten by _L. getulus_. However, one occasion reported herein shows that cottonmouths are eaten by king-snakes; and Clark (1949:252) reported finding 13 cottonmouths, along with other prey, in the stomach contents of 301 king-snakes (_L. g. holbrooki_) from northwestern Louisiana. Cannibalism is also common among cottonmouths. Klauber (1956:1058;1079) cited predation on cottonmouths by a blue heron (_Ardea herodias_) and a largemouth bass (_Micropterus salmoides_). Man is probably the greatest enemy of the cottonmouth. Intentional killing, capturing, road kills, and alteration of the environment destroy large numbers. Parasites and Diseases