160 Boeshore — The Morphological Continuity of 



the bundles show slight separation, thence to Epiphegus in 

 which the bundle system is loose and broken up into separate 

 bundles, which finally in Conopholis become still more widely 

 separated and distinct. 



As to the elements making up the bundles, the following is 

 stated by Wilson (25): "Each bundle of the inner row has in- 

 ternally xylem, made of xylem cells and well-developed spiral 

 tracheae. Next to the xylem is found the phloem, which in a 

 longitudinal section proves to consist of both sieve tubes and 

 companion cells. Adjacent to the phloem are a number of par- 

 enchyma cells, whose walls are so angular and so much thick- 

 ened that in the photograph these bundles appear to be bi-col- 

 lateral. That such is not the case, however, is easily proved on 

 longitudinal section, when the parenchymatous nature of these 

 cells is at once visible. Even in cross section, the color of the 

 walls differentiates the wood from the thickened parenchyma. 



The bundles of the exterior row have the same structure as 

 those of the interior, only the xylem is now exterior so that the 

 phloem masses of the two rows face each other." 



Sections stained in safranin and methyl green also some in 

 Delafield's haematoxylin and safranin bring out the bundle ele- 

 ments quite plainly. A different interpretation from the above, 

 however, is suggested with reference to the arrangement of the 

 elements of the bundle. Each bundle of the inner ring shows 

 internally phloem, consisting of a large patch of hard bast and 

 a patch of soft bast. The xylem comes next and is poorly de- 

 veloped, consisting of an interrupted line of cells, which are al- 

 most wholly large spiral tracheae, running across the bundle; 

 in some bundles there are several rows of spiral tracheae and 

 amongst them are several cells of phloem. Beyond the xylem 

 is another small patch of soft bast and next to it another small 

 patch of hard bast. The bundles of the outer ring show the 

 same elements, but in reverse order, small patches of hard and 

 soft bast, xylem, large patches of soft and hard bast. 



Comparative Study of the Inflorescence 



Regarding the inflorescence of the two supposed distinct fam- 

 ilies, several points are of special interest. In the parasitic 

 Scrophulariaceae the flowering axes are elevated above the sur- 

 face of the soil by the more or less elongated vegetative axes in 



