Figures 1, 2 and 3 depict the last of our weekly measurements of vine and root lengths.  We have decided to stop measuring them for two reasons: (1) there are so many roots in some of the bottles that it is extremely difficult to accurately keep track of them all; and (2) many of the roots have grown beyond the edges of the black felt material and have entered the gravel, where we cannot see them.  Again, we note the perplexing feature of this experiment to this point in time: there appears to be no further stimulus of growth beyond an atmospheric CO2 concentration of about 500 ppm.  Nevertheless, we also note that much remains hidden in the bulk of the gravel, and we have only been following the growth of one of the two plants in each bottle.