Figure 2.  Principle component (P'C) analysis of  fatty acid (FA) content of shad gills.  The calculated principle vectors on 39 samples with 39 FAs were used to extract the top three principle components of FA mole percent variation which were then plotted in 3-D stereo using the Kinemage program.  T0, T7 and T14 represent the treatment averages for shad in fresh water during the critical period of shad migration from fresh to salt water.  T0sw, T7sw and T14sw represent the treatment averages for shad transferred to salt water for 7 days prior to tissue sampling.  There is a meaningful (significant) effect in P'C-1 of the forceable maintenance in fresh water for 7 and 14 days as well as an effect of moving to sea water that depend on the date of transfer (i.e. there is an interaction between sea water transfer and date of transfer).  Additional meaning is also evident in the second and third P'C.  Use of principle components analysis may help to reduce the apparent complexity of the response.  Tests of additional information are applicable using the principles of  multivariate analysis of dispersion.