PLATE Y.° 
Fig. 1. Transverse section through a haustorium which has entered a 
root of Pavetta indica. The parts are still young and no 
vessels are formed. The nuclear cells are more vacuolated and 
less regular (a). At(a') the cells from a slightly older nucleus 
are shown. In the inner cortex there is a sharp distinction 
between the starchy (b) and protoplasmic cells (c’, the latter 
being elongated and taking part in the formation of the 
sucker. Secondary thickening is taking place in the cortical 
fold (d). 
Fig. 2. A haustorium fixed on a root of Santalum album. This may be 
taken as the type of the mature organ, as the vascular con- 
nection between host and haustorium is complete and the 
various tissues are becoming emptied of their contents. This 
is especially noteworthy in the breaking down of the cells at 
the top of the nucleus (a). Note also the endodermis (e) and 
the medullary rays (m.7.) in the transitional region, the 
cambium (c), collapsed layers and low-lying lacune (lac) 
inside them : also the bright cap of transparent yellow sub- 
stance (x) at the end of each of the host’s cortical wings. The 
structure of this is shown in fig. 4 of Plate VII. 6, hypoderm, 
