The William Matrimmatoe chant has several alternatives. "William Matrimmatoe" is sometimes replaced with "William, William Tremble Toe," "William a Trimmy Toe" or "William Trimble Trow Tran." Also, it sometimes ends with "But O-U-T spells out. So begone You dirty trout. You."
This rhyme is commonly credited with the origin of the title:
Vintery, mintery, cutery, corn,
Apple seed and apple thorn;
Wire, briar, limber lock,
Three geese in a flock.
One flew east,
And one flew west,
And one flew over the cuckoo's nest.
It is a variant of this Mother Goose rhyme that was printed in 1814:
Intery, Mintery, cutery corn,
Apple seed and briar thorn:
Wire, briar, limber lock,
Five Geese in a flock,
Sit and sing by a spring,
O-U-T and in again.
These two verses have some similarities and probably have common roots. However, I cannot find any information that links to the two. If anyone out there has any more insight, please let me know or note it yourself.
My source:
http://www.everything2.com/index.pl?node=One%20Flew%20Over%20the%20Cuckoo's%20Nest