In article <knowled.49.730568181 at ccsmtp.ccf.org> knowled at ccsmtp.ccf.org (Doug Knowles) writes:
>In article <23FEB199319244528 at elroy.uh.edu> psycpc at elroy.uh.edu (Rexer, Jennie L.) writes:
>>I have a question:
>>>>What is the origin of the decussated (I think I am spelling this correctly...
>>"crossed", in other words) central nervous system?
>>>>I have never heard a good explanation for this.
>>>>Also, how far down the evolutionary tree does this occur? All vertebrates?
Actually in his autobiography (Recollections of My Life - pp.
470-475), Ramon y Cajal discusses what he feels are the reasons for
the crossed nervous system. I will refer you to this book and his
original articles on the subject rather than trying to explain it here
and screwing it up. As I recall there were many papers that followed
from this theory so you should be able to find more on it.