THE ALLIGATOR'S LIFE HISTORY 107 



gives a very clear picture of the incubating temperature 

 of an alligator's nest and the development of the embryo 

 under normal conditions. 



Some writers state that in alligator's eggs, embryonic de- 

 velopment starts before the eggs are deposited in the nest. 

 This I have not found to be a fact, and I have examined 

 the fresh eggs from very many alligators' nests, also the 

 fully-developed eggs taken from many freshly-killed alli- 

 gators. The one egg opened from this nest the day laid 

 was without sign of embryonic development. It is possible 

 that should an alligator be kept from laying at the proper 

 time that her eggs should be laid, due to drouth or other un- 

 usual causes, that she will retain the eggs for a time in her 

 body, and under such conditions embryonic development 

 would start before the eggs are deposited in the nest. I 

 have seen this very thing in the eggs of fresh-water turtles, 

 when the turtles were kept during the laying season for a 

 considerable time on hard surface in which they could make 

 no nests, and therefore retained in their bodies eggs for 

 several weeks past the time when they should have been 

 laid. The embryos in such abnormally retained eggs begin 

 development in the parent, but if the eggs are retained too 

 long the embryonic deveopment ceases and the entire inside 

 of the egg becomes a tough, yellow mass. If embryonic de- 

 velopment has been found in the eggs of alligators while 

 retained in the mother, it should be considered an unusual 

 occurrence and due to irregular causes. Having examined 

 fresh eggs from hundreds of alligator nests, and the eggs 

 taken from hundreds of freshly-killed alligators without 

 ever finding embryonic development in such eggs, I make the 

 above statement with great positiveness. 



The following temperature records of this alligator's 

 nest taken with the bulb of the thermometer set at the cen- 

 ter of the egg clutch is, I believe, the first such record. It 

 is of interest to note that following rain the nest's tem- 

 perature was usually lowered. On days when there was no 



