The Scottish Naturalist. T99 



But there may be some present who are not familiar with the class 

 of plants in which we are specially interested ; and for their sakes 

 I may be pardoned if I make a few remarks of a general character. 

 The most cursory and superficial glance will recognise in every 

 scene a class of plants whose singular appearances, habits, and 

 modes of growth are so widely different from those of the trees 

 and flowers around that they might seem hardly entitled to a place 

 in the vegetable kingdom at all. On walls by the wayside, on 

 rocks on the hills, and on trees in the woods, we see tiny green 

 tufts and grey stains or parti-coloured rosettes spreading them- 

 selves, easily dried by the heat of the sun, and easily revived by 

 the rain. In almost every stream, lake, ditch, or any collection of 

 standing or moving water, we observe a green slimy matter form 

 ing a scum on the surface or floating in long filaments in the 

 depths. On almost every fallen leaf and decayed branch, fleshy 

 gelatinous bodies of different forms and sizes meet the eye. 

 Sometimes these different objects appear growing on the same 

 substance. If we examine a dead, partially-decayed stick, half 

 buried in the earth in a wood, we may find it completely covered 

 with various representatives of these vegetable growths ; and 

 nothing surely can give us more striking proof of the universal 

 diffusion of life. All these different plants belong to the second 

 great division of the vegetable kingdom, to which the name of 

 Cryptogamia has been given on account of the supposed absence 

 in all the members of those prominent organs which in the other 

 great division are essential to the production of perfect seed. 

 This Linnaean name is now, however, found to. be a misnomer, 

 for Cryptogamic plants are propagated by sexual elements as truly 

 as flowering plants, and these elements have been distinctly dis- 

 covered, even in the obscurest species. There is no actual gulf 

 x)f separation between flowering and so-called flowerless plants in 

 regard to their mode of propagation. They constitute links of a 

 common chain, in which as we proceed from the most simple to 

 the most complex, we trace the tendency of nature to specialise 

 more and more the parts devoted to a particular function ; just as 

 in a civilised community the same operations are performed by 

 the divided labour Of many individuals which in an early state of 

 society are executed by one. Cryptogamic plants are propagated 

 hy little embryo plants called spores or sporules, generally invisible 

 to the naked eye, and differing from true seeds in germinating 



