BROOM-RAPES, BALANOPHORE^, RAFFLESIACE^E. 



201 



termed a floral cushion. The cells in this cushion, however, now group them- 

 selves in a definite way; ducts and vessels are produced, and, at the same time, 

 a differentiation into axis and flowers is exhibited. These members continue their 

 development, increase in size, and finallj^ the enlarged bud breaks through the 

 cortex of the host-plant under shelter of which it has been evolved. 



In the genus Cytinus alone do we find a stem richly furnished with leaves and 

 bearing at the top a flattened symmetrical tuft of flowers (see fig. 42, left-hand 

 side) developed from this bud; in the rest of the Rafflesiaceae, the bud, which has 



Fig. 43.— EafBesiacese parasitic on trunks and branclies. 

 1 PilosttjUs Haussknechtii. ' Apodanthes Flacourtiana. 



Caulotreti, 



emerged from beneath the cortex of the host, is the flower-bud itself. The axis 

 supporting the bud is extremely abbreviated and clothed merely by a few scales, 

 and the flowers are sessile directly upon the root or stem of the host (see fig. 43). 

 In the case of roots creeping upon the ground, the buds always emerge only on the 

 side turned towards the light; on lianes, also, they are only formed on the side more 

 exposed to light where subsequently the opened flowers are easily accessible to 

 flying insects (see fig. 43 8); on upright shrubs and under-shrubs, on the other hand, 

 they burst forth on all sides upon the branches. Branches of this kind bearing 

 ubiquitously extruded flowers of a parasite such as Apodanthes Flacourtiana (see 

 fig. 43^) look delusively like the Mezereon {Daphne Mezereum) when the latter is 

 in bloom in the early spring before the development of foliage-leaves, its woody 

 branches being similarly studded all round with flowers, which stand out horizontally 



