GENERAL SUMMARY OF CRYPTOGAMIC GENERATION. 359 



breathe gently upon tlie glass, all the filaments will be instan- 

 taneously put in motion, — thus presenting an extremely curious 

 spectacle, — and will almost as suddenly return to their previous 

 condition, when the effect of the moisture has passed off. These 

 spores are to be regarded in the same light as those of Ferns ; 

 namely, as gemmce or rudimentary buds, not as seeds. They 

 evolve themselves after the like method into a prothallium ; and 

 this developes antheridia and archegonia, by the conjoint action 

 of which an embryo is produced. 



221. In ascending, as we have now done, from the lower to the 

 higher Cryptogamia, we have seen a gradual change in the gene- 

 ral plan of structure, so that the superior forms present a close 

 approximation to the Flowering Plant, which is undoubtedly the 

 highest type of Vegetation. But we have everywhere en- 

 countered a mode of Generation, which, whilst essentially the 

 same throughout the series, is essentially distinct from that of 

 the Phanerogamia ; the fertilizing material of the " sperm-cell" 

 being embodied, as it were, in self-moving filaments, which find 

 their way to the germ-cells by their own independent movements ; 

 and the " embryo-cell" being destitute of that store of prepared 

 nutriment, which surrounds it in the true seed, and serves as 

 the pabulum for its early development. In the lower Crypto- 

 gamia, we have seen that the embryo-cell, after fertilization, is 

 thrown at once upon the world (so to speak) to get its own 

 living ; but in the Liverworts, Mosses, and Ferns, the embryo- 

 cell is nurtured by the parent-plant, for a period that varies in 

 each case according to the nature of the fabric into which it 

 evolves itself. While the true reproduction of the species is 

 effected by the proper Generative act, the multiplication of the 

 individual is accomplished by the production and dispersion of 

 spores ; and this production, as we have seen, takes place at very 

 different periods of existence in the several groups, dividing the 

 life of each into two separate epochs, in which it presents itself 

 under two very distinct phases that contrast remarkably with 

 each other. Thus, the frond of the Marchantia, bearing its anthe- 

 ridia and archegonia, is that which seems naturally to constitute 

 the plant ; but that which represents it in the Ferns, is the mi- 

 nute Marchantia-like prothallium. On the other hand, the pro- 

 duct into which the fertilized embryo-cell evolves itself in the 

 Ferns, is that which is commonly regarded as the plant; and this 

 is represented in the Liverworts and Mosses by the spore-capsules 

 alone. We shall notice, in the next Chapter (§ 256), the repre- 

 sentation of these two phases in the life of the Flowering 

 Plant, which is traceable by means of the study of the Lycopo- 

 diaceae and Ooniferoe; two groups that form the link of transition 

 between these two great divisions of the Vegetable kingdom, 

 the former being probably to be regarded as the highest of 

 the Cryptogamia, and the latter as the lowest of the Phanero- 

 gamia.' 



' See the Author's " Principles of Comparative Physiology,'' Am. ed. 1854, §§ 499-505. 



