272 



THE MICROSCOPE. 



productive processes ; it will, however, be sufficient for our 

 purpose to notice the three leading forms. The first form, 

 to which the term polyspore has been applied, is that of 

 a gelatinous or membranous pericarp or conceptacle, in 

 which an indefinite number of sporidia are contained. 

 This organ may be either at the summit or base of a 

 branch, or it may be concealed in or below the cortical 

 layer of the stem. In some cases a number of sporidium- 

 bearing filaments emanate from a kind of membrane 

 at the base of a spheroidal cellular perisporangium, by 

 the rupture of which the sporidia formed from the 

 endochrome of the filaments make their escape. Other 

 changes have been observed ; however, they all agree in 

 one particular, namely, that the sporidium is developed 

 in the interior of a cell, the wall of which forms its 

 perispore, and the internal protoplasmic membrane en- 

 dochrome, the sporidium itself, for 

 the escape of which the perispore rup- 

 tures at its apex. 



The second form is more simple, 

 and consists of a globular or ovoid 

 cell, containing a central granular 

 mass, which ultimately divides into 

 four quadrate-shaped spores, which 

 when at maturity escape by rupture 

 of the cell-wall. This organ, called 

 a tetraspore, takes its origin in the 

 cortical layer. The tetraspores are 

 arranged either in an isolated manner 

 along the branches, or in numbers to- 

 gether ; in some instances the branches 

 which contain them are so modified in 

 form that they look like special or- 

 gans, and have been called stichidia ; 

 as, for example, in Dasya (fig. 149). 

 Of the third kind of reproductive or- 

 and two rows of tetra- gan a difference of opinion exists as to 



spores. Magnified 50 7i /? . j> ^i JT T 



diameters. the signification of their antheridia; 



although always produced in precisely 



the same situations as the tetraspores and polyspores, 



they are "agglomerations of little colourless cells, either 



