440 



NUTRITION. 



The weight of the egg-shell remained almost constantly the same. 

 The fat in the egg is of an uniform yellow colour before incubation, 

 although it undergoes various alterations during the development 

 of the embryo. On the seventh day a yellow oil was extracted by 

 ether from the thick yolk, while the fluid yolk yielded first a 

 yellow and subsequently a colourless fat. The membranes and 

 the albumen yielded a transparent white oil, the liquor amnii a thick 

 white fat, and the embryo a white fat like lard. On the fourteenth 

 day the oil of the yolk became yellow and thick ; the same was 

 the case with the oil of the membranes ; that of the albumen was 

 colourless and thick; that of the embryo reddish and solid. On the 

 twenty-first day the fat of the yolk became thick and of a pale 

 yellow colour, and that of the membranes dark yellow and partially 

 solid ; ether extracted from the embryo a fat which at first was solid 

 and yellow, but at a later stage was white and soft. 



We will now simply subjoin the results of the ash-deter- 

 minations. 



Un-incubated eggs contained in 



Eggs, after twenty-one days' incubation, contained in 



According to Baudrimont and St. Ange, the absorbed oxygen 

 is to the oxygen exhaled in the carbonic acid as 100 : 54'9 during 

 the period of the development of the hen's egg from the 9th to 

 the 12th day, and as 100 : 81'0 from the 16th to the 19th day, a 

 fact which is entirely in accordance with the circumstance that it is 

 i n the last third period of incubation that the greatest quantity of the 



