FAMILY CARES — NURSERY DUTIES. 153 



markings take the form of scribblings all over 

 the egg, and so on. The exact meaning of 

 these various patterns of coloration is unknown, 

 and perhaps will for ever remain so. 



The colouring matter of the egg is deposited 

 during the passage down the oviduct — the long 

 coiled tube leading from the ovary or place 

 where the eggs are formed to the outer world. 

 The walls of this oviduct secrete or manufacture 

 the colouring matter. The spots, streaks and 

 blotches which add so much to the beauty of 

 the egg, tell how the pigment, or colouring 

 matter forming the same, was deposited. Thus, 

 spots show that the pigment was deposited 

 whilst the egg was at rest, blurred markings, 

 whilst in motion. Sometimes the motion seems 

 to have been rotatory inasmuch as the markings 

 are spiral in character, as is well seen in the eggs 

 of many guillemots. 



For the most part birds nearly allied lay similar 

 eggs, but there are many exceptions to this rule. 

 The general truth of this fact, however, is un- 

 questionable. It was the recognition of this that 

 led ornithologists to perceive the close relation- 

 ship between the gulls and ploveis which, till 

 then, had always been considered very distantly 

 allied; other and anatomical characters were 

 later brought to light which confirmed their 

 observations. 



The texture of the shell varies much. It may 

 be most extraordinarily smooth and polished re- 

 sembling burnished metal or highly glazed porce- 

 lain, as in the tinamous, or smooth and greasy as 

 in the ducks; or covered with a thick chalky 



