JULY FLOWEKS. 115 



all round, and then dropping off, as it ripens, into little 

 articulated pieces, each containing a single seed. The 

 pod, in fact, divides at the joints between the beans, and 

 so disappoints the birds, who always wait in other cases 

 till the valves burst open. Wild radish, or " jointed 

 charlock" as the farmers call it, has independently 

 adopted the self-same plan in the widely different fam- 

 ily of the cresses. As to peculiarities in the number 

 and shape of the seeds themselves, the hairiness or 

 smoothness of the pods, the color and consistency of 

 their coverings and so forth among the peaflowers alone 

 they are practically innumerable ; and each has its own 

 definite purpose, generally discoverable in the end by a 

 little careful observation and minute comparison. 



The leaves, again, vary immensely, though always 

 strictly by derivation from a single ideal or ancestral 

 type. The typical leaf of the pea-kind has a central 

 stalk, with little leaflets arranged in opposite pairs along 

 its course, and a similar terminal leaflet at the end. This 

 is the form the foliage still assumes in lady's-fingers, 

 bird's-foot, and many other species. But in the clovers, 

 and similar stunted creeping meadow plants, there is not 

 much material to spare upon the leaves, and so they only 

 develop one terminal leaflet with a single pair of lateral 

 ones beneath it : in other words, they are shortened into 

 trefoils. The complementary leaflets on each stalk 

 remain always undeveloped. In these vetches, again, 

 and still more in the true peas, it is the terminal leaflets 

 that are wanting ; and in their place the end of the 

 common leaf -stalk lengthens out into twining tendrils, 

 which help the branches to creep over other plants, so as 

 to gain a decided advantage in the struggle for life over 

 the little procumbent clovers. 



Sometimes among the peas, however, circumstances 



