236 



HOMOLOGIES OF THE 



CUAP. VIII 



SO many groups of spiral vessels, in every case traced 

 down to one of the six large ovarian groups. They 

 alternate in five whorls, as represented ; but I have not 

 attempted to give the actual distances at which they 

 stand apart. In order to guide the eye, the three 

 central groups running to the three pistils are con- 

 nected by a triangle. 



Fig. 36. 

 Upper or posterior sepal. 



Upper ^ 

 petal. 



Upper 

 petal. 



Labellum. 



Section of the Flower of an Orchid. 



The little circles show the position of the spiral vessels. 



Ai 



SS. Stigmas; Sr, stigma modified 

 into the rostellum. 

 Fertile anther of the outer 

 whorl ; Ag A3, anthers of the 

 same whorl combined with 

 the lower petal, forming the 

 labellum. 



flj Gj. Rudimentary anthers of the 

 inner whorl (fertile in Cypri- 

 pedium), generally forming 

 the clinandrum ; Oj, third 

 anther of the same whorl, 

 when present, forming the 

 front of the column. 



Five groups of vessels run into the three sepals 

 together with the two upper petals ; three enter the 



