204 SYSTEMATIC POSITION OF MITHA^TEMOX. 



Iiecome very much finer luitil at last the tluead cDusists of a siugle row of 

 eells, which is called by Soljis-Laubach a mycerium-thread, ou accouut of 

 its resemblauce to a fuugus-hypha (SoLiis-LArBACH II., Goebel I., p. 435). 

 Accordingly iu every cross section of a regiou iu or uear the place wliere a 

 flower-peduncle stauds, we shall invariably find in the Ijast a number 

 (30-50) of lounded points, each distinct aud remot<', or sometimes coming 

 iuto contact and uuiting, every one of which is a cross section of a horizontal 

 thread, ariangod iu a liug or two all rouud the xylem. Each of these poiuts 

 throws a perpendicular thread through tlie cambium layer aud xylem, aloug a 

 medullar}- ray towards the center. Tho surface view of the network of 

 hoiizoutal threads in the bast is clearly and easily observable with the 

 naked eye in the process of removing the outer xwts of the secoudary bast. 

 Therefore, the intr-amati-ical tissue in the bast forms a cyHuder-like liody 

 made of reticubited threads, which completely suiTounds the xylem outside 

 the cambiura layer. It is .justly comparable iu some respects to tliat of 

 Cythms which Hes in the bast as a true, pei-fect, but uureticulated cyhnder 

 iuside the cambium layer. The thalhts of Mitrademoa bcai-s even mure 

 resemblance to that of Burgnwnsw (Solms-Laubach, IY.) and Pijlostj/Us 

 (Soljis-Laubach II.. LoTSY p. 882). Such a stracture of the intramatrical 

 tissue is considercd, at the present time, to be a character peculiar to the 

 RafflesiaceiE and uever observed iu auy other family. The only counec- 

 tion of this tissue to one of another kind which we call a " senker," is to 

 be foiuid in ArceidhMnm Oxi/cedri, a plant belongiug to the Loran- 

 thacejB (GOEBEL II., p. 379). The perpendicuhxr threads are by no means 

 terete like the horizontal, but are laterally compressed. Accordingly iu the 

 cross sectiou of a vertical thread, wliich is obtainable in a tangential section 

 of the host-root, it comes into view as a lentiform group of cells ahvays 

 laying side by side with a medullary lay, or sometimes layiug in a group of 

 bast celLs. It is broader aud thicker towards the base (i. e. the bast), but 

 narrower aud thinner towards the center of the xylem, aud at last becomes 

 a thread consisting towards the apex of a single row of cells. 



Thereforo, in a lougitudinal section vi the host-root, aud also in a cross 

 section of the sarae, the veiiical tlneads always appear iu the shape of au 



