569 



in some cases extends three 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 twenty cm from the top and in the nests 

 found were lying on top of one another making fine 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 4 5 mm; in length they vary from 67 to 88 mm. The shell 

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

 is also thicker than that of the hen's egg and consists of an inner and an 

 outer layer; the fibres of both extend obliquely around the egg 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 toward either end being much more 

 opaque white. The white of the egg has the consistency of a very 

 thick jelly so that it Avill adhere to the yolk 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 color; 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 be- 

 tween yelk and membrane and which Avhite 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 



