CRYPTOGAMIC VEGETATION. 7 



becomes at first bicellular, by transverse division in 

 the centre, then each cell is subdivided in like manner, 

 and the spore becomes four-celled ; less frequently, 

 by biseptation of each cell it is six-celled, or by 

 partition of each one of four cells it becomes eight- 

 celled. Very rarely, when the septation is complete 

 does each cell exceed its own diameter in length, 

 and as rarely is the number of cells three, five, or 

 seven. 



In the ascomycetous fungi, the sporidia, to the 

 number of four, or eight — rarely two or sixteen — are 

 contained in membranous sacs, but never three or 

 five. These sporidia, in the majority of instances, 

 are continuous, but in some at first continuous and 

 afterwards two or more celled. In all cases, whether 

 in the moulds or the ascomycetes, each cell possesses 

 all the properties and functions of an individual 

 spore ; so that, after all, the reproductive unit is 

 reduced to a single cell. The same remarks apply 

 also to the lichens, which are, at least, the analogues 

 of the ascomycetous fungi. 



In support of the hypothesis that compound spore. 

 in fungi are families of individuals, as in algse, we 

 may quote Phraguiiditcvi amongst the uredincs, and 

 Fusaruon amongst the moulds. In the former, each 

 of the four to eight cells is perforate, and produces 

 its own germ-tube, at the end of which the small 

 protospores are developed, each cell being as much 

 an individual as the single cell in Uromyces. In the 

 latter there is sometimes even a dehiscence at the 

 joints, whilst each cell germinates independently, and 

 can reproduce the original mould as completely as 



