40 MISSISSIPPI EXPERIMENT STATION. 



The leaf mesophyll is rather dense in each of the three plants 

 under comparison, being made up of spongy parenchyma and palisade 

 cells in about equal amounts (figs. 51, 52 and 53). There are 2 to 4 

 layers of the palisade cells, being 2 - 3 in Radish and 3 - 4 in the other 

 two plants. In Radish, these cells are about 45^ in length, while in 

 Kohlrabi, they are 33^ long and in the hybrid about 40^. 



Surface sections of the leaves show stomates on each side, there 

 being a few more on the under side than on the upper. On either side, 

 the stomates seem to be rather uniformly distributed. The guard 

 cells are about the same size in each of the three plants. Mounts made 

 from the Radish leaf show about 40 stomates, on the average, in the 

 microscopic field (1 inch ocular and 1-6 inch objective), when mounts 

 are made from the under side of the leaf and 30 when from the upper; 

 Kohlrabi shows 28 and 22 respectively and the hybrid 38 and 30, the 

 average numbers of the three for both surfaces being 35, 24, and 34. 



The regular epidermal cells from the under side of the leaves seem 

 to differ considerably in the three plants, when viewed in surface view. 

 In Radish, they have a wavy, sinuo.s outline (fig. 44), and average 

 about 75m in length; in Kohlrabi, they are more or less irregularly 

 rectangular, without a wavy outline, and average about 45^ in length 

 (fig. 42) ; in the hybrid they have about the same shape as in Kohlrabi, 

 but they are considerably longer, being about 70m in length, nearly as 

 long as the corresponding cells in Radish (fig. 43). 



A comparative study of the microscopical structure of the flowers 

 of the three plants has not been made. However, ovaries and young 

 anthers of the hybrid were sectioned. The ovaries and young ovules 

 seemed to be perfectly normal in the sections examined, but further 

 study and experiment is needed to determine whether or not they 

 would form seed, providing the pollen element was normal. Sections 

 of the young anthers showed pollen mother cells beginning to disinte- 

 grate or break down while in the resting stage. 



