302 MR. W. GRIFFITH ON THE GENUS GNETUM. - 
must likewise advert to this period when they state the nucleus to be surrounded with 
three envelopes. | i 
The nucleus, which up to the present time continues free from adhesion, has now — 
undergone a slight alteration in figure, consisting in a tendency to constriction towards 
its apex, which is now invariably more or less brown: its cavity has become enlarged, 
This constriction may possibly be only apparent, since it may originate in the greater 
growth of the elevated part of the depression, stated to exist at the apex. : 
- As the young seed progresses in its development, the two outer coats increase in size, - 
The base of the additional membrane adheres to the corresponding portion of the nucleus, | 
the adhesion continuing to increase in extent until it has reached upwards to the com- : 
mencement of the constriction. The projecting tubular prolongation does not appear to 
have any regular term of existence; its coloration or sphacelation increases, and at a 
variable period the exserted portion becomes detached at the situation of the opening of 
the outer coat. The cavity existing in the nucleus undergoes a corresponding enlarge- - 
ment, and its walls are more irregular. It will be found to contain, about the period of 
detachment of the exserted portion of the tubular process, a pendulous body of a similar — 
form, attached by a rather broad cellular band to the apex of the cavity. This is the — 
rudimentary amnios, developed originally within the sac, stated to line at a prior period - 
the cavity of the nucleus. As the development proceeds, this body increases in size; it — 
appears to be developed from below upwards, and as it enlarges, the lax cellular attach- 
ment undergoes a corresponding diminution, chiefly, I imagine, by pressure. As this 
body, in which the albumen becomes deposited, increases, the substance of the nucleus d 
gradually disappears, and subsequently merely forms a thin covering to the large and — 
fleshy albumen. The last change which I have traced in the albumen consists in the for — 
mation of a cavity within its substance, commencing at its apex, and gradually extending — 
downwards. The corresponding changes consist in the development of pulp and increase — 
of the fibres of the outer coat; in an induration (rather in an induration of the second 
envelope depending upon the development of fibrous tissue) and development of fibrous 
tissue in the second envelope, which subsequently becomes brown, subosseous, and fragile. 
The originally large and distinct openings through both these become narrowed, but never. 
completely filled up—not, at least, by an extension of their own substance. The additional 
envelope is now membranous and thin, united throughout the greater part of its extent 
to the thin remains of the nucleus. The included (and permanent) portion of its ori in» 
ally tubular prolongation has become filled up, and is embraced closely within the con 
stricted openings existing through the two outer coats. The remains of the nucleus, 
owing to the pressure this has undergone during the growth of the albumen (or rather of 
the amnios and deposition of albumen), finally assume the form of a membrane, united, 
except towards its apex, which is brown or black ånd apiculate, to the inner paries of the 
third coat. : is — 
Mi h regard to the development of the embryo, I can add nothing. Although I hav 
examined abundance of fully-formed fruits of two species, I have never observed anything 
towards the development of the embryo beyond the formation of the cavity in - 
albumen, and the very rare and partial development of the funiculus, which, moreover, i 
