Johnson & Gii.mokk — Dewalquea in Coal-bore at Washing Buy. 331 



Dewalquea shows certain Juglandaceous characteristics not to be 

 overlooked in seeking to ascertain its systematic position. Principi's 

 D. grandifolia shows a pinnate leaf of 5-7 leaflets derivable from the types 

 illustrated in the earlier works quoted. The transition from the pedalo- 

 digitate to the impari-pinnate leaf is not difficult to follow. In the seedling 

 of Pterocarya frcixinifolia Spaeh., the two cotyledons are deeply four or five- 

 lobed, and may be described as pedalo-digitate. Such a form of seed-leaf 

 makes it unnecessary to look to the Hellebore for an explanation of Deivalquca's 

 leaf. Examination of the adult pinnate leaf of Pterocarya (and of other 

 genera of the Juglandaceae) shows the presence of peltate scales or glands 

 which bear a striking resemblance to those of Dewalquea. In Engelliardtia 

 the likeness is such that (PI. XII, fig. 12) one might easily be mistaken for 

 the other. 



The epidermal cells show similar sinuous lateral walls, cuticular surface 

 striae, and similar stomata. There is the sam.e difference in the edge of the 

 leaf as in Dewalquea. The edge may be entire or serrate in both genera — 

 in different species in Juglans — but, according to Berry, possibly in the same 

 species (or even plant) in Deivalquea. This difference of the leaf-margin is 

 accompanied by a slight difference of venation, which is, generally speaking, 

 camptodrome in Juglans. In this genus the cross-anastomoses connecting 

 the secondary veins run straight and parallel to one another in most cases ; 

 but in Enyelhardtia they are jointed and branched and irregular, as in 

 Deivalquea. The secondary veins bifurcate and join together, giving a 

 marginal network much as in Deu-alquea. The Juglandaceae are a primitive 

 group allied to the Amentaceae and Myricaceae. Though Juglans is now 

 confined, in Europe, to the south-east corner, it was widely distributed 

 throughout the continent in Tertiary times, having travelled southwards from 

 the Arctic regions. Until fruits are found the question must remain open ; 

 but one may provisionally regard Detocdquea as an ancestral Walnut. 



[BiBLIOGKAPHY. 



