The Clythrae: The Egg 



outer threshold in the hkeness of an acorn 

 fixed in its cup. 



Nothing could be prettier than this yellow 

 egg, standing in its artistic egg-cup. Nor 

 could anything tell us more conclusively 

 where the jewel is manufactured. It is in 

 the cloaca, the chamber common to the ovi- 

 duct and the intestine, that the bird wraps 

 its egg in a calcareous shell, often decorating 

 it with magnificent hues: olive-green for the 

 Nightingale, sky-blue for the Wheatear, soft 

 pink for the Icterine Warbler. It is in the 

 cloaca also that the Clythra and the Crypto- 

 cephalus produce the elegant armour of 

 their eggs. 



It remains to decide upon the material em- 

 ployed. From its horny appearance there 

 is reason to believe that the little barrel of 

 the Taxicorn Clythra and the scales of the 

 Four-spotted Clythra are the products of a 

 special secretion; and, now that it is too late, 

 I much regret that I neglected to look for the 

 apparatus yielding this secretion in the neigh- 

 bourhood of the cloaca. As for the thing 

 so prettily wrought by the Long-legged 

 Clythra and the Cryptocephali, let us admit 

 without false shame that it is made of faecal 

 matter. 



469 



