5S 



all granular contents ; it is not till after the addition of the outer coat that the gru- 

 mous granular matter is secreted." — 491. 



The germination of the sporules is minutely described by the author. 



" The first external sign of germination is either the appearance of four cells pro- 

 jecting through the apex of the conical projection, or a gradual swelling of that part. 



* * The enlarging cellular mass then distends the conical projection, unfolding 

 the plicae of that body, and at length appears externally with four of its cells project- 

 ing beyond the general mass, and compressed into a quadrangular form. * * 

 Soon after the exposure of the entire germ, which is effected by the reflection of the 

 valves [of the internal membrane] and conical membrane over the side of the sporule, 

 where they lie quite concealed by the germ, little fibiillee or rootlets begin to shoot 

 from one side. They are simply articulated tubes, or elongated cells applied end to 

 end, with frequently a bulbous extremity ; and each is produced from one of the cells 

 of the germ." — 485. 



Shortly after the appearance of these rootlets the cells of the germ 

 become flatter and more intimately connected with each other ; and 

 at the same time that part of the germ which closes the cavity of the 

 sporule becomes hollow- and afterwards points in two places. These 

 points gradually lengthen, and on dissection each will be found to 

 consist of a closed sheath, one containing the first leaf and the other a 

 root : these two apparently distinct sheaths communicate with each 

 other, and envelope nearly the whole of the germ. The young leaf, 

 when rather longer than the sporule, bursts through its sheath, and 

 the root protrudes before it is as long as the sporule. 



" After the leaf has grown to be many times the length of the sporule, or about 

 two lines long, another leaf grows from the germ close to the first, to which it is in all 

 respects similar ; and then a bud begins to be developed from some indefinite part of 

 the germ, but like the leaves and root, from within the sheath, which is now frequent- 

 ly much lacerated. This bud is covered by a peculiar kind of jointed hairs, whose at- 

 tachments are lateral, at a short distance from their bases, and which contain a few 

 colourless granules. This bud sometimes appears after the first leaf, in which case 

 there is no second primordial leaf formed ; and is the rudimentary stem, the first 

 growth from it being a leaf, which exhibits, although in a small degree, the first evi- 

 dence of gyration, and shortly after a root, which is furnished with its own sheath. * 



* The roots are all formed in sheaths, through the apices of which they ultimately 

 burst, the sheath continuing to embrace the base of the root, whilst a distinct and far 

 more delicate sheath closely embraces its point." — 487. 



" This account of Pilularia shows that it is incorrect to say of Acrogens that * ger- 

 mination takes place at no fixed point, but on any part of the surface of the spores ;' 

 for it is quite certain in this instance that germination invariably takes place at a fixed 

 spot, which maybe pointed out before germination has commenced. It is at that part 

 of the sporule indicated by the three radiating lines which appear to have been produ- 

 ced by the pressure of the three other sporules that originally helped to constitute the 

 quaternary union ; and as the spores of all the other tribes appear, according to Mohl, 



