INTRODUCTION TO CRYPTOGAMIC BOTANY. i5 



threads they put out produce in fact the true fruit. This holds 

 good equally of all the blight or rust like Fuugi, such as affect 

 corn and other living plants.* 



32. A different order of things prevails amongst the higher 

 Cryptogams. The spores germinate and produce a more or 

 less foliaceous mass, which after impregnation bears fruit 

 containing bodies like the original spores, or a plant capable of 

 bearing such spores, in which case it is called a prothallus. 

 (Fig. T4.) After a time, certain pitcher-like processes project 

 from it, or are sunk in its substance. A cell at the base of these 

 urns, when impregnated, grows after the fashion of the first 

 cell of the embryo in Phsenogams. In some cases, then, the 

 cells which arise from germination are developed, as in mosses, 

 into a plant directly, reproducing spores by which the cycle is 

 again accomplished ; in others, as in Ferns and Club-mosses, 

 an embryo more or less resembling those of Phsenogams is 

 first generated, which strikes root and sends out an ascending 

 stem, which sometimes grows into an enormous tree, pro- 

 ducing every year a crop of spores. The spores, then, in these 

 different plants are of very different values, and in no respect 

 homologous with the seeds of plants. Crj^ptogams have, in fact, 

 no true separable seeds,though, in the highest forms which they 

 assume, they generate an innate embryo. Without some such 

 notion, though I am obliged to anticipate matters to be described 

 more fully hereafter, it is scarcely possible to estimate the true 

 relations of Cryptogams to Phsenogams. 



33. I shall proceed now to explain the points of difference 

 and resemblance which exist between Club-mosses and Conifers, 

 for if any Cryptogams are allied, it must be these.-f- Selaginella, 

 for example, produces two kinds of spores, a smaller and a larger, 

 in closed processes. Externally, and in their mode of gen- 

 eration, both these resemble the spores of allied Cryptogams, but 



* This seems to be a sort of alternation of generations. The first cycle 

 is completed by the well-known reproductive bodies ; the second by the 

 spores produced on their germinating threads. 



t For figures illustrative of the text look forward to the section on 

 Club-mosses. For full information, Hofineister's two Treatises must 

 be consulted. 



