370 Mr, R. Brown on the Plurality and Development 



In this stage the upper extremity of the included body^ or am- 

 nios, is shghtly concave, and has a more or less rough or unequal 

 surface ', the inequality being in consequence of the laceration of 

 the cellular tissue, by which it was in its early stage attached to 

 the apex of the original nucleus, or rather to a short cylindrical 

 process arising from it and corresponding in size and form with 

 this concave upper extremity, from which it separates when the 

 amnios has attained its full size. 



On this concave upper extremity of the amnios a few minute 

 points of a deeper colour, and disposed in a single circular series, 

 are sometimes observable ; in general, however, they are hardly to 

 be distinguished. 



Below the concave apex the amnios itself is slightly transpa- 

 rent for about one-fourth of its length, the remaining portion 

 being entirely opake. 



On dividing the whole longitudinally it is found to consist of 

 a pulpy cellular substance, in which no definite cavity is originally 

 observable ; the upper transparent portion is however of a looser 

 texture, and on the included embryos becoming manifest, a cavity 

 irregular both in figure and extent is formed in its centre. 



But before the embryos themselves or their funiculi become 

 manifest, the areolae, or portions of the substance destined for their 

 production, are visible. 



These areolte, as I observed them in the common larch in May 

 1827, are from three to five in number, of nearly cylindrical form, 

 arranged in a circular or elliptical series, and are seated near the 

 apex, with which they probably conmiunicate by the similarly ar- 

 ranged points of its sm-face already noticed. 



In the amnios of Pinus syhestris, as observed in June and July 

 last, the corresponding parts w ere found considerably more ad- 

 vanced. In the specimens then examined, the remains of the em- 

 bryoniferous areolse, from four to six in number, were still visible, 

 but consisting of conical membranes of a brown colom*, present- 

 ing their acute apices towards the surface, and at the base seem- 

 ing to pass gi-adually into the lighter-coloured pulpy substance 

 of which the mass of the amnios consists. 



Corresponding and nearly approximated to each of these co- 

 nical membranes, a filament, generally of great length, and either 

 entirely simple or giving off a few lateral branches, was found. 

 This filament or funiculus consisted generally of four series of 

 elongated transparent cells or vessels, visually adhering together 

 with firmness, but in some cases readily separable without lace- 

 ration ; and in one of the species examined, Pinus Pinasfe?; the 

 transverse septa of the funiculus wxre either very obscure or alto- 

 gether wanting. 



