METAMORPHOSIS. 



133 



division of the normal one, the products belonging to 

 the posterior half of each lateral sepal. Buchenau 

 described 3-spurred flowers (fig. 116). In the vast 

 majority of cases he observed that the presence of 

 extra spurs was correlated with the complete absence 

 of a bract. In some cases the extra spur or spurs were 

 turned inside out and solid. In a 4-merous flower, in 

 which the sepals were diagonally placed, he found the 

 single spur placed opposite the posterior petal. Such 

 anomalous positions for the spurs as he repeatedly 



s 



116 117 

 Fig. 1 1 G. — Tropseoluvi majns (Indian Cress). Flower with three spurs 

 (sp) opposite the petals (p) ; s, sepals. 

 Fig. 117. — Tropxolum mojus. Peloric flower; no spur present. 

 Diagrams. (After Buchenau.) 



describes in his paper, as in the last-mentioned case 

 and the one seen by the present writer, may probably 

 be accounted for by the fact that the three posterior 

 sepals completely dominate that region of the flower ; 

 the posterior portion of what appears to be the 

 receptacle really represents the fused basal portion of 

 the three sepals, and its coloration is the same ; and as 

 the insertion of the posterior petals is a very slender 

 one the basal spur-bearing portion of the calyx may 

 actually overlap the petal-insertion, as would seem to 

 be the case in Buchenau's 4-merous flower. Such a 

 condition of affairs would fully explain the abnormal 

 position of the spurs. In any case the view held by 

 Buchenau, Dammer, and others, that the spur repre- 



