684 



Mutations' 



Leaves placed in whorls of three are very rare. 

 The oleander, jumper and some few other 

 plants have ternate whorls as a specific char- 

 acter. As an anomaly, ternate whorls are far 

 more common, and perhaps any plant with op- 

 posite leaves may from time to time produce 

 them. Races rich in this abnormality are 

 found in the wild state in the yellow loose- 

 strife or Lysimachia vulgaris, in which it is 

 a very variable specific character, the whorls 

 varying from two to four leaves. In the 

 cultivated state it is met with in the myrtle 

 or Myrtus communis, where it has come to be 

 of some importance in Israelitic ritual. Crisped 

 leaves are known in a mallow, Malva crispa, and 

 as a variety in cabbages, parsley, lettuce and 

 others. The orbicular fruits of Heeger's shep- 

 herd's purse (Capsella heegeri) recall similar 

 fruits of other cruciferous genera, as for in- 

 stance, Camelina. Screw-like stems with wide 

 spirals are specific in the flower-stalks of 

 Cyclamen and Vallisneria, varietal in Juncus 

 effusus spiralis and accidental in Scirpns lacus- 

 tris. Dormant buds or small bulbs in inflo- 

 rescences are normal for wild onions. Polygo- 

 num viviparum and others, varietal in Poa 

 alpina vivipara and perhaps in Agave vivi- 

 para, and accidental in plantains {Plant ago 

 lanceolata), Saxifraga umbrosa and others. 



