Page:Popular Science Monthly Volume 68.djvu/60

56 I have often noted abnormal developments or possible reversions which have suggested to me another explanation. These offer much evidence that instead of the ear originating from the fusion of a number of two-rowed spikes, it developed directly from the central spike of some tassel-like structure similar to the well-known corn tassel. Tassels may be found where only a few pistillate flowers have been formed on the central spike and others with more and more such

flowers, up to where a fair-sized ear has been developed. The accompanying photograph (Fig. 1) shows some of the steps from a normal tassel up to a perfect ear. Note that in the first step the plant is almost normal (at the left), in the second the central spike of the tassel is fairly well developed into a small ear, the number of lateral branches has been somewhat reduced, and the internode below the tassel is somewhat shortened, so that the base of the tassel is partly enclosed. In the third step all the lateral branches have disappeared but two, and the