162 M. Geoffroy Saint- Hilalre on some Bones and Eggs 



The objects which I have the honour to place before the Aca- 

 demy, are the two entire eggs, a piece of the shell of the broken 

 egg, and some osseous fragments, one of which especially, as will 

 be seen, is of great interest to science. 



The two eggs which are now before the Academy differ little 

 in size, but much in form. One of them has the two ends very 

 unequally convex ; the other represents almost exactly an ellipsoid 

 of revolution. The following are the dimensions : — 



Ovoidal egg. Ellipsoid egg. 

 metre. metre. 



Long diameter 0-34* 032 



Transverse diameter 0225 0'23 



Large circumference 085 084 



Small circumference 0"71 072 



e. m. 



Size „ 0008887 



The thickness of the shell is about 3 millimetres. 



We shall give comparatively the principal measures, taken or 

 calculated in the same manner, with the Ostrich and the other 

 large birds of the same group, and with the Hen : — 



Ostrich. Rhea. Casowary. Emu. Hen. 



m. m. m. m. m. 



Large circumference 046 035 0365 0335 01 6 



Small circumference 0-425 030 029 027 0-14 



cm. cm. cm. cm. cm. 



Size 0001527 0000735 0000532 000526 0000060 



The thickness of the shell, larger in proportion, is in that of 

 the Ostrich 2 millimetres. It is 1 millimetre with the Casowary, 

 and less with the other birds. 



According to the preceding measures, it appears that the ca- 

 pacity of the egg of the large bird of Madagascar is about 8| litresf, 

 and that, to represent its size, it woidd requ.ire nearly 6 eggs of 

 the Ostrich, 12 of the American Ostrich or Rhea, \Q~ of the 

 Casowary, 17 of the Emu, and 148 of the Hen. We may add, 

 contrasting with each other the two extremes of the series, that 

 this same bulk is equal to that of 50,000 eggs of the Humming- 

 bird. 



Are the eggs which have just come to us from Madagascar, 

 those of an immense reptile or of a gigantic bird ? This was the 

 first question which suggested itself on their discovery. The 

 examination of their shells, the stracture of which is similar to 

 that which is observed in those of the large birds with rudimen- 

 tary wings, and particularly of the Emu, would have sufficed 

 for the solution of this question ; but it is given much more di- 

 rectly and completely by the bony fragments which have come 



* In English measm-e the ovoidal egg is about 13| inches by 8| inches. 

 — H. E. S. 



t A litre is =61-028 English cubic inches.— H. E. S. 



