Glynn Davies asks the question as to what causes the egg to change its
orientation and tip downwards over a three day period. The question is good,
but I'm not sure that the premise is right. I should sit down sometime and
observe what happens to eggs in the comb. Occasionally it is instructive just
to check that what we have all taken for granted is in fact the case.
 
Elbert Jaycox referred to this, citing work by Dr E J DuPraw in 1961, who
concluded that the egg did not change position until about an hour before the
larva is ready to emerge from the shell.
 
I look forward to reading what others have observed. In the meantime, I have
just had an experimental nucleus hive built for a university which
incorporates Jenter-type cages built into the comb, accessible from the back
without disturbing the small colony, specifically for examining eggs, while
knowing exactly how old the eggs are. With any luck, I may be able to get some
feedback from the researchers.
 
Matthew J Allan
Manager, Thornes of Windsor
European Editor, Bee Biz