66 Papers from the Marine Biological Laboratory at Tortugas. 



hind flippers alternated in scooping the sand from the nest until a cylin- 

 drical hole was dug nearly as deep as their length. The alternation from 

 right to left was perfectly regular. Neither flipper ever took sand from 

 the hole twice in succession. 



After the hole was completed the turtle assumed a position so that 

 the cloaca was very nearly over the center of it and began to lay at once. 

 The cloaca projected fully 2 inches during the process of laying. The 

 head was well extended and flat on the ground. The anterior end of the 

 body was raised so that the ventral surface made an angle of about 20 

 with the horizontal. There was no arrangement of the eggs in the nest 

 as fishermen sometimes assert. The eggs were dropped from the cloaca 

 into the hole in a series of one or two at a time at intervals of from 4 to 

 8 seconds. Two were deposited together about every fourth time. Dur- 

 ing the discharge of the eggs the hind flippers were slightly raised, and 

 in one case (witnessed at night earlier in the summer) there was heavy 

 breathing which was very distinctly heard. In the turtle under present 

 consideration, however, not the slightest sound was detected. 



Fishermen often say that after a turtle begins to lay it will continue 

 even if it is turned on its back. I did not try this, but I did strike the 

 turtle a sound blow on the head with a heavy stick, using both hands, 

 at two different times while she was laying. She withdrew her head, 

 moved slightly to one side and stopped laying, but only for a few mo- 

 ments. Noise and gentle contact did not appear to affect her in the least. 



It is commonly thought that the loggerhead turtle ordinarily lays 

 three times during each summer, about 150 eggs the first time, fewer the 

 second time, and about So the third. I did not ascertain precisely how 

 many eggs were laid by the turtle under observation. It is almost 

 impossible to remove the eggs from the nest without killing the embryos, 

 and, since there have been many trustworthy observations on the number 

 of eggs laid, it seemed unnecessary to destroy the young for the sake 

 of learning the exact number in this particular nest. 



Immediately after the eggs were discharged the turtle began to 

 cover them. In doing this she moved the posterior end back and forth 

 much as she did in digging the hole. As this end proceeded to the right 

 the left flipper was thrust backward into the sand and then suddenly 

 moved inward so as to throw and scrape the sand on to the eggs immedi- 

 ately back of it. As it proceeded to the left the right flipper acted in the 

 same way, but of course it threw the sand in the opposite direction. Thus 

 the turtle filled the trench as well as the hole, stopping frequently to 

 pack the sand, especially that over the eggs. This she did by placing 

 the posterior pointed end of the body on the sand and elevating the 

 anterior end so as to bring her full weight to bear upon it. After the 

 trench was nearly filled she turned about over the region several times 

 and threw and scattered the sand in every direction with all four flippers 

 so as to conceal the place, especially that where the eggs were laid. 

 This completed she returned to the sea and entered only a few feet from 

 the spot where she came out. On the way down the beach I stood on her 

 back and she carried me (165 Ibs.) apparently with but little effort. 

 From what has been said regarding the concealment of the nest of the 



