484 Mr. VALENTINE on the Structure and Development 
softens and expands by the action of water, but is not completely dissolved. 
The larger bodies, the undoubted sporules, after a very slight maceration in 
water—less than a minute is sufficient—are enveloped by a well-defined cover- 
ing of gelatinous matter, which before the maceration existed in a concrete 
state (Tas. XXXIV. fig.3.). Further maceration does not appear to affect this 
gelatinous covering, as it remains unchanged long after germination, and gives 
to the sporule the appearance of baving a very delicate transparent border, 
whose breadth is about the fourth part of the diameter of the sporule. The 
sporule consists of three coats, the outer of which is white, opake, somewhat 
brittle, more or less incomplete at the conical extremity, but much thickened 
about the upper third of the sporule, where it exhibits traces of cellularity. 
The middle coat is membranous, elastic, of a light yellowish-brown colour, 
and perforated at the apex of the conical projection (Tas. XXXIV. fig. 5.), 
which is essentially formed by this coat, the outer coat being gradually lost 
upon its surface, or in some instances being scarcely continued on to it; in 
which case the sporule appears truncated, the middle membrane not having 
sufficient firmness of itself to support the conical form (Tas. XXXIV. fig. 4&5.). 
This conical projection is more or less plicated ; and in those instances in which 
the outer coat is very deficient, the middle membrane exhibits lines radiating 
from the aperture. The third coat or internal membrane is similar in colour 
to the middle, differing from it, however, in being inelastic and not being con- 
tinued into the cone, but forming a short cavity by passing directly across the 
base of the cone, at which point it is not in contact with either of the other 
membranes, and is marked by three lines, which radiate from the centre of 
the unsupported portion, and indicate a valvular structure to allow of the 
protrusion of the growing matter in germination (Tas. XXXIV. fig. 6, 8, 9, 
&11.). [The cavity of the sporule is occupied by a quantity of grumous fluid 
and particles which are of various sizes, the larger ones being mostly of an 
ovoid shape, but altering by pressure (Tan. XXXIV. fig. 6 & 7.).] 
I found many of these sporules in a germinating state, the majority having 
escaped from the involucrum ; but in several instances I found them consider- 
ably advanced in germination before the rupture of the involuerum and whilst 
they were yet inclosed in their sacs. The first external sign of germination is 
either the appearance of four cells projecting through the apex of the conical 
