Egg embryo is adequately developed it hatches, i.e. breaks out of the egg's shell. Some embryos have a temporary egg tooth they use to crack, pip, or break the eggshell or covering. The largest recorded egg is from a whale shark, and was in size. Whale shark eggs typically hatch within the mother. At and up to , the ostrich egg is the largest egg of any living bird, though the extinct elephant bird and some dinosaurs laid larger eggs. The bee hummingbird produces the smallest known bird egg, which weighs half of a gram (around 0.02 oz). Some eggs laid
François Lays on a high note, sent the minister a petition signed by almost all the stars of the Opéra and backed by Cherubini, asking for another benefit concert, in addition to the one three years earlier, this time in aid of his son who was working as a "saute-ruisseau"' at a notary’s and whose legal studies Lays could not afford to maintain. Inevitably the request fell on deaf ears. Lays also asked for his pension to be recalculated, bearing in mind his years teaching at the conservatory. But this led to disputes to which the correspondence between Cherubini and La Rochefoucauld