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 (Tab. 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 having 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 (Tab. XXXIV. fig. h.), 

 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 (Tab. 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 (Tab. 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 (Tab. 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 involucrum 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 



