Hi Dave According to Ruttner (1988) the discoidal shift was introduced by Goetze (1964) and extensively studied by Louis (1963).
According to geometric morphometrics instead of using the discoidal shift index you should use coordinates of the three points which define it. By doing this you should obtain much more information about wing venation. Best wishes Adam Tofilski ----- Original Message ----- From: "morphmet" <[EMAIL PROTECTED]> To: "morphmet" <[email protected]> Sent: Friday, June 22, 2007 5:45 PM Subject: Discoidal Shift in honey bees > Hi all > > I have been looking into refining some aspects of honey bee morphometry > and a question has arisen about defining/identifying the points required > to calculate Discoidal Shift. > http://www.dave-cushman.net/bee/wingmeasurement.html > > But with variations in the shape of the anterior end of the radial cell > using the 'extreme tip' can lead to significant variations in the > result. What I cannot find is an authoritative statement defining the > correct way of ascertaining the points. > > Who invented the method? Goetze? > > Has anybody any knowledge or insight into the problem ? > > Reply address... > Dave Cushman > [EMAIL PROTECTED] > > > > Regards & Best 73s, Dave Cushman, G8MZY > http://website.lineone.net/~dave.cushman or http://www.dave-cushman.net > Short FallBack M/c, Build 6.02/3.1 (stable) > > > > -- > Replies will be sent to the list. > For more information visit http://www.morphometrics.org -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
