MR. W. GRIFFITH ON THE GENUS GNETUM. 303 



the only two cases in which I observed its partial formation laid loose in the cavity. 

 Excepting the want of this essential portion, the seeds were, as I have since ascertained 

 by comparison with seeds with perfect embryos, fully and completely formed. 



The following description of the matm-e seeds is taken from exembryonate specimens, 

 and from the examination of some embryonate seeds of Gnetum seandens, brought from 

 Arracan, and communicated, with many other interesting productions, to Dr. WaUich by 

 his late friend Captain R. R. Margrave : — 



The mature seed is more or less ovate, obtuse, or acute, and of a reddish-orange colour, 

 and either entirely smooth, or covered with appressed, peltate, silvery cellular scales. Its 

 coats occur in the following order : — 



1. Outer and baccate. Origin : outer envelope of ovnle. — Of this the outer half is 

 entirely cellular ; the inner composed of several layers of fusiform fibres, sharp at both 

 ends, of a yellow colour and shining appearance. They are often punctated, and occa- 

 sionally marked with incomplete spiral fibres ; they are pungent, and occasion considerable 

 irritation. 



2. Drupaceous : originatvnc/ from the second envelope of the ovule. — ^This is externally 

 sulcate, the innermost fibres of the outer coat being lodged in these sulci ; it is of a brown 

 colour and nearly osseous texture, composed of cells, the innermost series of which are 

 arranged transversely, and a great number of longitudinally-disposed fibres, which are 

 longer and of much less diameter than those of the outer baccate coat. 



3. Fibro-cellular coat. Origin : the additional envelope, and chief part of the nucleary 

 membrane. — The external part, which is composed of fibres similar to those of the drupa- 

 ceous coat, arranged longitudinally, is terminated by the persistent and now woody por- 

 tion of the originally tubular prolongation, the apiculus being lodged in the opening 

 existing even at this period in both the outer coats : its apex is discernible exteriorly at 

 the corresponding end of the seed, but does not, however, project beyond the level of the 

 outer coat. The internal portion forms the 



4. Cellular and membranous envelope. Origin : the circmnferential tissue of the 

 nucleus, — This adheres to the preceding throughout the greater part of its extent. Towards 

 the apex, where it is thinnest, most membranous and sphacelated, it is free, and it is 

 terminated by a conical point (the original elevated portion of the centre of the depressed 

 apex of the nucleus) : it is free from adhesion with the former coat. The point, however, 

 always separates with the albumen, the upper portion of which it covers somewhat in 

 the manner of a cap. 



5. Albumen. Origin : a deposition in the tissue of the amnios. — This fills exactly the 

 cavity of the last-mentioned envelope ; it is of considerable size, fleshy, and abounds in 

 feculent granules. Around its apex an indistinct areola is visible, and to its extreme 

 apex are attached the remains of the originally lax, cellular attachment ; its base is like- 

 wise marked with a depressed, indistinct areola. Along its centre, and occupying the 

 upper half* of this portion, there is a cavity of considerable size, which tapers off in- 



* With regard to the a:ds at least ; otherwise the base of the original amnios corresponds to the apex of the 

 nucleus. 



