24 BREEDING 



the nodes which produce normal and fasciated stems. 

 We shall now deal with characters of the pods ; first 

 with differences in texture, and then with differences 

 in colour. 



The third character, with which Mendel experi- 

 mented, which we shall consider is therefore the 

 shape or, more strictly, the texture of the pod. The 

 pods of all the varieties of culinary pea commonly 

 grown possess a tough, parchment-like lining, which 

 makes the immature pod inedible and the axis of 

 the ripe pod straight (in the sense that a horse's 

 back is straight), and its surface even, as shown 

 in the right-hand pair of pods in Fig. 9. For 

 brevity in reference, this type of pod may be called 

 *' hard." There is also a variety of pea, the pods of 

 which lack this tough lining, the absence of which 

 renders it possible for the immature pods to be eaten 

 — and very good they are. They are called sugar 

 peas in England and Germany, and the variety is 

 described as sans parcliemin in France. The absence 

 of this parchment-like lining has a very noticeable 

 effect on the shape of the pod throughout its develop- 

 ment. The main axis of the pod, unsupported by 

 this tough tissue, becomes much bent and contorted, 

 and the two flanks of the pod collapse on to the 

 seeds, so that the contour of the seeds can be clearly 

 seen on the outside of the pod, and the surface of 

 the ripe pod is generally uneven, as is well shown 

 in the left-hand pair of pods in Fig. 9. We may 

 conveniently refer to this type of pod as 

 " soft." 



