I do not have a citation for you; however, I am interested in the question.  
I must admit to being baffled.  Why include size measurements in your 
analysis at all, unless somehow the measurement of shape is derived from the 
size measurement.  If you've measured only bone lengths, which surely would 
vary greatly in size, then how did you arrive at a shape measurement?

M.C.

>From: Richard Wright <[log in to unmask]>
>Reply-To: "Classification, clustering, and phylogeny estimation"            
>   <[log in to unmask]>
>To: [log in to unmask]
>Date: Mon, 23 May 2005 12:06:54 +1000
>
>This is a question about size and shape in morphometric studies.
>
>I have a series of measurements of bone lengths in individuals that vary 
>greatly in size. I want to consider similarities and differences between 
>the individuals solely in terms of shape. To remove differences in absolute 
>size I have taken each individual, summed all the measurements for that 
>individual, and then divided each measurement by that sum.
>
>This is an intuitively simple method. Some years ago I read a 
>recommendation about using it. Now an editor is asking me to cite a 
>reference to the use of the method. Unfortunately I cannot recollect where 
>I saw it advocated.
>
>Can anybody help?
>
>I know that there are various alternative methods for eliminating size in 
>multivariate morphometric work, such as eliminating the first principal 
>component if that is one of general size. However my question is not about 
>the competing merits of size/shape methodologies in general. This is a 
>specific request for a citation of the approach outlined above.
>