SYSTEMATIC POSITIOX OF MITRASTEilOX. 203 



SoLMS-L.vuBACH YI.). Fmit baccate, slightly larger than tlie ovary, and com- 

 parable to tbat of the Apodantheae. In the case of a xilant -svhich was seut 

 from its native locality, aud kept gi-owing in a pot in a green-hoase here in 

 Tokyo, I have observed that the style which at the base is jointed to the 

 ovary is, when the frait is fully rix>e, separated by a slit along the articula- 

 tion. Seeds miuute and \evy nnmerous, with a hard reticulated testa Uke 

 those of rafHesiaceous plants. 



III. Inner Morphology of Jlifvastemon, especially 

 with regards to its systematic Position. 



1. Auatomy of the intiamati-ical Tissue. 



The intramati-ical tissue of the parasite in the host root is entirely of 

 the kind generaUy called a "thanns" wliich, iu its maiu parts, exists in 

 the bast of the host root. It is a formless mass just under the pedimcle of 

 a flower in the bast and soon separates into a number of threads nuiuing 

 right and lef t along the loug axis of the host root ; auastomosing witli eacli 

 other, and formiug a network which completely suiTOunds tlie host-root iu 

 the middle layer of the bast and ou the outer side of the cambium layer. 

 Flower peduncles are generaUy found most profusely ou roots 1 cm. or more 

 iu diameter. From each thrcad of the network-thallus a uumber of smaller 

 thi-eads much iiuer than the preceding are seut out perpendicular to it 

 towards the eeuter of the xylem. For couvenience sake, I shall ca,ll a 

 thallus-thread ruuning horizontally along the long axis of the root in the 

 bast-region a horizontal thread, and one nmning vertically towards the center 

 of the sylem a vertical thread. The horizoutal threads in the bast are com- 

 posed, as is seeu in a cross sectiou of the host root, of rounded plasmatic 

 celLs in the periphery, but of a elongated ones towards the center, aud in 

 most cases there are foimd uear the ceuter some tracheids with spiral 

 markings. The periphei-al plasmatic cells, it seems to me, are comparable 

 to the phlom of highly orgauized plants iu their function, while the central 

 somewhat elougated tracheidal celLs resemble the xylem of the same in theii- 

 function. Towards their euds, the threads, both vertical and horizoutal, 



