H0FME1STER, ON THE HIGHER CRYPTOGAMTA. 435 



second generation is to form numerous free reproductive 

 cells — the spores — by the germination of which the first 

 generation is reproduced. The leafy plant in the mosses 

 answers therefore to the prothallium of the vascular 

 cryptogams ; the fruit in the mosses answers to the fern 

 in the common sense of the word, with its fronds and 

 sporangia. The pro-embryo, that is to say the confer- 

 void process produced by the germinating spore of most 

 of the mosses and many of the liverworts, cannot be 

 looked upon as a special generation any more than the 

 similar organ (the suspensor) in phsenogams. It is to be 

 remembered that when new individuals are produced from 

 single cells of the leaf of a moss, and also during the 

 development of the gemmae of many mosses, the formation 

 of the rudiment of the first leafy axis is preceded by the 

 formation of a similar confervoid pro-embryo. This holds 

 good as well in the mosses * as in those liverworts which 

 possess a pro-embryo. When new individuals are formed 

 from the fragment of a leaf of Lophocolea heterojpliylla or 

 of Badula complanata, the cell of the surface of the leaf 

 which becomes the mother-cell of the new plant produces 

 in the former of the above-named plants a single or double 

 row of cells, and in the latter a cellular surface. In each 

 case the body produced is exactly similar to the pro- 

 embryo which originates from the germinating spore in 

 both species. 



The vegetative life of the mosses is confined exclusively 

 to the first, and the fructification to the second generation. 

 The leafy stem alone sends forth roots : the spore-forming 

 generation draws its nourishment from the first generation. 

 The life of the fruit is usually much shorter than that of the 

 leaf-bearing plant. In the vascular cryptogams this state 

 of circumstances is reversed. It is true that the prothallia 

 send out capillary roots ; this is always the case in the 

 Polypodiacege and Equisetaceee, and frequently in the 

 Rhizocarpeae and Selaginellse. But the prothallium lives a 

 much shorter time than the leaf-bearing plant, which latter 

 in most cases does not produce fruit for several years. 



* W. P. Schimper's excellent work, ' Reckerckes sur les mousses,' readers 

 it unnecessary for me to cite examples. 



