510 Miscellaneous. 



growth of palmettos, mangroves, magnolias, &c. These are called 

 " hummocks " by the natives. On one side of the hummock at 

 least, in some cases on all sides, is a pond from ^ to 2 metres in. 

 depth, and in the bank, under the water, the female alligator digs 

 a cave which in some cases extends 3 metres under the hummock 

 and which is always close to her nest. The nest is made by 

 scratching together a great pile of dead leaves and twigs and humus 

 which forms the surface of the ground, and which is arranged with 

 some care ; the inside is made of the more finely divided, almost 

 powdery material of the deeper layers of the top soil, while the 

 outside even to the top is covered with twigs and leaves which are 

 whole or but little broken, and with many of the long unbroken 

 leaves or needles of the southern pine. The eggs are deposited 

 about 20 centim. from the top, and in the nests found were lying on 

 top of one another, making rows or layers with the fine humus 

 filling all interstices. The top of the nest is always well exposed 

 to the sun. 



The eggs are white, elliptical, and vary in the shorter diameter 

 from 39 to 45 millim. ; in length they vary from 67 to 88 millim. 

 The shell is thicker than that of a hen's egg and more brittle ; the 

 shell-membrane is also thicker than that of a hen's egg and consists 

 of an inner and an outer layer ; the fibres of both extend obliquely 

 around the e^^ and those of the two layers are always at right 

 angles to each other ; the shell-membrane is most closely attached 

 to the shell in a zone around the smaller diameter, which varies 

 greatly in width, and wherein the membrane is less translucent 

 than towards either end, being much more opaque white. The white 

 of the egg has the consistency of a verj^ thick jellj , so that it will 

 adhere to the yelk after the shell-membrane has been removed to 

 such a degree that the whole egg can be held on the palm of the 

 hand and transferred from one hand to the other. The yelk is 

 spherical, large, and of the faintest yellow or straw-colour ; it is so 

 large that it nearly touches the shell-membrane in the middle line 

 of its opaque zone, leaving but an extremely thin layer of white 

 between yelk and membrane, and which white adheres very closely 

 to the membrane throughout the opaque zone : this layer of white 

 grows thinner as incubation proceeds and a very light watery liquid 

 increases. 



After the first day it is almost impossible to get off the membrane 

 without rupturing the thin pellicle of white ; and if this be done, 

 the embryo is carried away with the outflowing liquid and is 

 quickly broken into innumerable pieces. 



They are for these reasons the most difficult eggs that I have ever 

 tried to work with. 



Very often the opaque zone is larger at one point, and that always 

 marks the position of the embryo ; when the zone is of equal breadth 

 throughout it is impossible to determine its exact position. 



Examining an egg on the day after they were found, and finding 

 that no change had occurred, I concluded to pack them all carefully 

 and get back with them as quickly as possible to my laboratory, 

 where I could have the best facilities for the difficult work in hand. 



