150 THE AMERICAN MIDLAND NATURALIST 



That turtles can exist under water, perhaps indefinitely, during cold weather 

 is shown by the many records of finding them under ice. On the other hand 

 painted turtles and those of other species taken in traps in summer die quickly 

 or are in a weak condition when removed from the water. At least two factors 

 doubtless contribute to these phenomena; first, the amount of oxygen dissolved 

 in cold water is much greater than that in warm and hence more is available 

 for buccal and cloacal respiration in winter; second, physiological activities are 

 greater in warm weather than in cold and the necessity for oxygen is therefore 

 increased. 



Painted turtles are omnivorous. They will eat crayfish, earthworms, snails, 

 insects and their larvae, fish, carrion — including dead birds, mice and turtles 

 — and a variety of aquatic plants. In captivity they exhibit a fondness for 

 meat and for almost all green vegetables. In all the numerous observations 

 made upon them both in the field and in captivity they swallowed their food 

 under, or at the surface of the water. 



A pair was discovered in what was presumed to be a mating position 

 April 19, 1931, along the shore of Indian Lake, in Logan County, but unfor- 

 tunately they separated before any detailed observations could be made. None 

 were seen in coitu in captivity but it is probable that pairing ordinarily occurs 

 in early spring. 



Nesting normally takes place in June. A specimen in the Toledo Zoo was 

 observed digging its excavation and laying its eggs the evening of June 15, 

 1934. The work was begun at twilight and was carried out in much the same 

 way as has been described for the nesting of the box turtle (page 140) ; the 

 total time consiuned was somewhat over two hours. The eggs, which were 5 

 in number, failed to hatch. 



A female with a carapace 5% inches long which had just deposited its 

 eggs was discovered on the road at Cedar Point, Lucas County, June 17, 1933. 

 It had dug through the hard surface and made its hole in the softer soil be- 

 neath. Its eggs were yellowish flesh in color and had rather brittle leathery 

 shells which were easily indented by the fingers. They were more or less 

 capsule shaped and several had a circular whitish area, about 10 mm. in diam- 

 eter upon their shells. The eggs, which were 8 in number, varied from 8.4 to 

 9.2 grams, average 8.7 grams in weight; and from 28 to 32, average 30 mm. 

 in length and from 17 to 18, average 17.5 mm. in width. 



A female collected on Little Cedar Point, June 8, 1935, was kept in a pail, 

 and laid eggs intermittently from July 2 to July 11, until a total of seven had 

 been deposited. Another female was discovered at Bono, Lucas County, in 

 the act of starting her nest at twilight June 25, 1935. 



Juveniles in which the navel scar was soft and large and which were judged 

 to have been out of the egg only a short time were collected on a number of 

 occasions. These measured an inch or slightly more in carapace length. 



