AND PECULIAR FORM OF THE EMBRYO IN THE CLUSIACEjE. 251 



various attributes have been assigned. This determination is fortunately assisted by the 

 drawings of Dr.Roxburgh, whose details, always accurately observed, are copied byDr.Wight 

 in his ' Icones,' where in pi. 192. fig. 12 & 13, is shown a seed of Xanthochymus dulcis, 

 in a state of germination, together with a longitudinal section of the same: here is 

 depicted precisely the same linear process (the neorhiza), which is throwing out a root 

 from the basal speck I have described, while the apical nipple of this same process has 

 simultaneously become extended considerably, carrying upward with it the leaflets of the 

 growing plumule : from the lower part of the neck thus protruded, and beneath the two 

 lower scales which I have designated as the cotyledons, a second rootlet is seen to sprout, 

 tending first horizontally and then downwards. We have here unquestionable proof that 

 the process in question is what I have called neorhiza ; for were it the embryo imbedded in 

 albumen, as Gsertner affirms, it would not throw out descending shoots at the upper por- 

 tion as well as the base ; nor would the same result follow if it were the radicle, according 

 to the view of Dr. Graham. The fact is certainly fatal to the conclusions of Choisy, 

 Cambessedes, and other modern botanists, that the great mass of the nucleus consists of 

 two confluent cotyledons, and that the mamm reform apex seen in the seed of the Clmiece 

 is its radicle, even if this opinion had not been disproved by the structural appearances 

 which I have already described, and which are still further confirmed by a more minute 

 examination of its internal organization. 



On placing a thin transverse slice of a seed of IApophyllum {Clusia, Camb.) under the 

 microscope, it will be seen to be of a reticulated texture, and composed of a number of 

 small hexagonal cells filled with yellowish grumous viscid matter, except in the centre, 

 across the line of the neorhiza, where the cells cease to be distinguishable : close to the 

 periphery, and corresponding with the external striae which I have described (p. 246), a 

 circle of about fifty very conspicuous ducts is observed, each duct having a diameter 

 three times that of the reticulated cells : they are separated from each other by one or 

 two rows of the same kind of cells that fill the main area, the circumference of the nucleus 

 being formed of a very thin epidermis lined with parenchyma. On examining another 

 slice of the same seed, cut in a vertical direction parallel with the axis, a somewhat 

 different appearance is manifested ; the cells no longer seem reticulated, but form regular 

 longitudinal channels, interrupted by transverse septa placed at distances nearly equal to 

 their diameter, bearing the semblance of articulated tubes or muriform tissue ; they cease 

 to appear along the line I have designated as the neorhiza : the large ducts near the 

 margin are entire and hollow tubes with simply striated surfaces, and are filled with a 

 yellow secretion of a more fluid nature than that of the cells, though still somewhat 

 viscous. The neorhizal portion appears formed of longitudinal and exceedingly m inute 

 lines, exhibiting a uniformly striated opake and whitish texture. I have observed, in 

 the seeds of the genus Quapoya, a structure exactly similar to that just described, 

 except that in addition to the external row, a few similar longitudinal ducts filled with 

 yellow fluid appear interspersed within the main area. M. Cambessedes, in his figure of 

 Clusia Criuva before referred to, has depicted on the outer surface of the nucleus the same 

 external striae, but he makes no allusion to the circumstance in the text. 



It is requisite to offer some observations upon the nature of the external covering of 

 VOL. xxi. 2 L 



