384 THALLOPHYTES. 



CLASS IV. 



CARPOSPORE^. 



Under the name of Carposporeae I include in a single class the Coleochaeteae, 

 Characeae, and Floridese on the one hand, all of which contain chlorophyll, and on 

 the other true Fungi, namely the Ascomycetes, Basidiomycetes, and ^icidiomycetes. 

 The remarkable differences of their habit and mode of life offer no real obstacle to 

 such an arrangement, any more than do the similar differences which exist between 

 the Lemnacese and the Palms to their being both included in the class of Monocoty- 

 ledons. In this case, as in that, it is the peculiarities which accompany the forma- 

 tion of the reproductive organs and become especially prominent in the product of 

 fertilisation that indicate the existence of a relationship between plants which are at 

 first sight so different. 



All the plants belonging to this class are characterised by the formation of 

 a spore-fruit {sporocarf) as the result of the fertilisation of the female reproductive 

 organ, and differ herein from all those which have hitherto been considered. This 

 spore-fruit consists, except in certain cases in which it is rudimentary, of two distinct 

 parts, a fertile part, which is directly derived from the female organ and which pro- 

 duces at a later period one or more commonly numerous true spores, and an 

 investing part, which encloses the spores. Occasionally this fruit attains a very con- 

 siderable size, as, for instance, in the Truffle : in other forms it may remain com- 

 paratively small. In all cases, however, fertilisation not only causes a further 

 development of the female cell, as in the Zygosporese and Oosporeae, but certain 

 processes of growth are initiated which may lead to comparatively insignificant 

 results (as in Characeae), but which are usually of an extensive character, so that 

 a sporocarp is produced consisting of a considerable mass of tissue. In those cases 

 in which the sporocarp remains relatively small, and in which it continues to derive 

 its nourishment from the parent-plant until the spores are ripe (as in Characeae, 

 Florideae, Coleochaeteae, and in some Fungi), it seems to be a mere appendage, like 

 an apple on a tree : but in those cases in which it attains a considerable size, grows 

 for a length of time and finally produces numerous spores, after that the parent- 

 plant has decayed, an alternation of generations becomes apparent. Such is the 

 case among the true Fungi, especially in the Ascomycetes. In these, the fructifica- 

 tion continues to grow for some time, and presents the appearance of being a 

 perfectly independent plant. In fact, it is usually but erroneously regarded as being 

 the whole Fungus, whereas it is only the product of a process of sexual reproduction 

 which has taken place on the vegetative body, the mycelium. In such cases the 

 process of the life-history of the plant is similar to that of a Fern ; the insignificant 

 mycelium corresponds to the prothallium, and the well-developed sporocarp of the 

 Fungus to the spore-bearing Fern. If we consider from this point of view the 

 various ways in which the fruit is formed among the Carposporeae, we shall find that 



