134 



s. MATSUDA. 



The pith consists of iinh'onified cells, and is traversed in places by 

 a kind of horizontal septa. This structure is known as " diaphragms " 

 (PI. Y, Fig. 27, dm'), and is universally found in tlie species included 

 in the present tribe. In some species, cjj., ]\fafiH(ih'(t (jrmnliflora, it is 

 very conspicuous and distinctly visible to the naked eye as streaks 

 traversing the pith. A diaphragm consists of a horizontally stretched 

 mass of scleroblasts, whicli, when highly developed, occupies an almost 

 entire cross section of the pith, though it is inconsiderable in thick- 

 ness; and this mass is continuous at several points with the wood- 

 parenchvma that lies at the inner limit of the xylem. In Liriodcndron 

 the greater part of a diaphragm consists of cells with thick, ])itted, 

 but not lignified walls, while the remaining small ])orti(m is made u]) 

 of scleroblasts. The diaphragms of Müijnolia Inipolcuea consist of 

 scleroblasts having a very irregular shape. Those of MaiptoUa par- 

 r i 11 ara iuid 31. sal ici fol id are not so well developed as those of other 

 sjiecies. 



rctioh'. — Tlie cuticle is strongly developed in Michelia, but not 



in Liriudcndron. In Mü(juolia it is well developed in some species, l)ut 



less so in others. Epidermal hairs are abundantly found in Michelin, 



l)ut in Liriodoidrou they are almost absent. In M(ujuoJi(( many species 



have the hairs well developed, while some are destitute of them. In 



DffKjHoIia jiarvifJora and a variety of MmjuoJin ohorala (KdH.diiu-inolii- 



rcii) there are found, in addition to the kind of hairs common to other 



species, smaller haiis which are sometimes l)ranched (PI. V, Tig. '24, 



cli). The hairs are generally cuticularised, but in MdtjNolia Kohus, in 



which a few are found, they remain cellulose. Resin-sacs occur in 



the outer cortex of all the species, and even in the ])hloëm of some. 



The scleroblasts, which are often many-armed, are generally found in 



the external cortex ; but in the single ca.-e of TÀriodcndron they are 



almost absent. The number of hbro-vasculnr l)uiidles which entei' 



