OF BÜCKLEYA QUADRIALA, B. ET H. 17 



has ever been clearly mentioned in none of these. Pitra 11 has 

 given a cambium-like tissue in Thesium, but in very ambiguous 

 terms : " Zwischen diesen GefêLssbogen den ganzen Raum ein- 

 nehmend, ferner auf ihren äusseren Seiten, also die Gefassbündel 

 rundherum umgebend, liegt ein Gewebe aus dünnwandigen, mit 

 trüber Flüssigkeit erfüllten Zellen, welches die Gefässbündel in 

 das Gewebe der Nährpflanze begleitet ; es kann als Cambial- 

 gewebe der Saugwarze und der Saugwurzel betrachtet werden, 



" Thus judging merely from its structure, he regarded 



the central parenchyma which I call here the pith as being 

 similar to the parenchyma outside the vascular strand, but he 

 did not mention whether the function of these two parenchymas 

 is idential or not. Solms-Laubacil'-' observed on the outer- 

 most parenchymatous cells of the axis (Kern) in Thesium, "die 

 gestreckter, dünnwandiger Zellen, wie sie in Weichhast und 

 Cambium vorkommen." Hieeonymus :,) also considered that pa- 

 renchyma as the " an Cambium erinnernden Gewebe." Even 

 in the case of haustorium of Santalum and Osy ris, of which the 

 secondary growth is more than probable, no particular attention 

 has ever been paid to this feature. From my study in Buckleya, 

 however, it is clear that the parenchyma immediately bordering 

 the vascular strand is the cambium and it is almost certain that 

 if the secondary growth occurs in the haustoria in other Santalaceœ 

 it should be performed by means of this meristem interposed 

 between the axial part and the cortex. 4 ' It must be understood 

 then that this parenchyma should properly be separated from the 



1). loc. cit. p. 14. 



2). toc. cit. p. 54:;. 



3). loc. cit. p. 205. 



4). In fact Solm-Laubacii's figure of Osyris (Taf. XXXII, Fig. 7 and 8) shows that the 

 haustorium is in at least its second year, for the sucker is imbedded in the wood of the In >st 

 as in the case of an old haustoria of Buckleya. 



