MONIMIACE^. 321 



aroma is due to an oleo-ethereal substance contained in the cortical 

 parenchyma. Its colour, varying from yellow to reddish-brown, 

 indicates its presence in certain cells, which are sometimes as 

 thin-walled as the surrounding cells, sometimes thickened like the 

 sclerous cells of the JFinterece, and riddled with large perforations. 

 The wood of the Monimiacea is generally soft,' and is always 

 remarkable for the number, size, and distinctness of the equidistant 

 medullary rays. These all consist of nearly equal cells, which have 

 always appeared to us full of starch and finely punctate. The woody 

 bundles present no very peculiar character. Like some of the 

 vessels, the fibres are pitted, and the perforations are either circular, 

 elliptical, or even nearly linear and transverse {Peumus). Very 

 often, too, their openings are surrounded by an areola of the same 

 form as themselves, but this is narrow, and not nearly so well 

 defined as in most Mapioliacece. These pores are, then, inter- 

 mediate between the areolate pores observed in certain orders and 

 the common perforations of fibres or vessels. They are found in 

 great numbers in certain vessels of Peumus and Hortonia, covering 

 the whole of the walls so that we can find no trace of arrangement 

 into distinct vertical rows. In the same plant we may find some 

 pores rounded or oval, others like more or less elongated slits. 

 This fact was observed by Tulasne, who has seen the walls of 

 certain vessels partly destroyed and cut up into scalariform or can- 

 cellate plates. According to the same observer, the woody fibres are 

 narrow and elongated, and the medullary sheath, as usual, contains 

 spiral vessels. But these have often appeared to us very scanty. 

 The axes of the CaJi/canthea alone present one very remarkable 

 peculiarity observed for the first time by B. de Mirbel,- in 1828, 



^ We should except certain woods employed tenius {Ein. Beoh. iib. d. Bau der Bignon., 



in building, especially tbe AtherospermecB (see p. Linncea (1847), 580) has seen them appear in 



327). the young branches, as four isolated liber 



- Note surV Organisation de la Tige d'tin Irh- bundles in the cortical cellular tissue. On the 



vieux Calycanthus floridus du Potager royal de side towards the axis of the branch arise spiral 



Versailles, Ann. Sc. Nat., ser. 1, xiv. 367, t. vessels, within which are developed woody fibres 



xiii. " The four bundles each present a proper and dotted vessels. At the age of five years the 



cortical envelope, woody layers, one above an- liber bundles are still unaltered, while the wood 



other, large vessels forming zones in the wood, has doubled in thickness. — See also TKEViKiNTS, 



rays prolonged from the centre to the circum- Fhys. d. G^ewrtc/w. (1835), i. t. i. 10. — Henfret, 



ference, and a medullary canal." This fact Ann. of Nat. Hist., ser. 2, i. 125. — Lindl., 



has been reproduced, re-observed, or commented Introd. to Bat., i. 209; Teg. Kingd., 541. — 



on by very many authors. Link (Fkor., iVVwe Kk^tm, But. Zeit. (1859), 109.— Oliver, op. 



Notiz., xxxiv. ; Flora (1845), 558), has studied cit., 13. 

 the composition of these cortical bundles. Met- 



VOL. I. Y 



