16.] CHAPTER II. SPECIAL MORPHOLOGY OF THE MEMBERS. 75 



times very elaborate, for its dehiscence. In a few cases the whole 

 sporangium falls off from the parent plant, e.g. the microsporangia 

 and macrosporangia of Salviniaceae ; here the spores never become 

 free from the wall of the sporangium, but germinate inside it. 



(?>) The Sporophore. Beginning with the lower plants, a well- 

 marked asexual spore-producing organ is, in many cases, a striking 

 feature of the incompletely sexual gametophyte j this organ, on 

 account of its being borne by the gametophyte, is distinguished as 

 a gonidiophore, and its spores as gonidia (see p. 3). It is to be 

 found in many Fungi, where it represents, in fact, the shoot of the 

 body, and is a specialised, erect-growing branch of the mycelium. 

 It may be simple (e.g. Mucor, Peronospora, Eurotium) or compound 

 (Agaricus) ; in some cases it bears sporangia, or rather gonidangia, 

 in which gonidia are formed (Mucor, Peronospora) ; whilst in 

 others (Eurotium, Agaricus) it bears short filaments, termed 

 sterigmata, from which the gonidia are formed by abstraction. In 

 some Ascomycetous Fungi the simple gonidiophores which form 

 gonidia by abstriction, are collected into groups (son), each of 

 which is enclosed in a receptacle, the whole constituting a pycni- 

 dium. Among the Algae, the gonidiophore is represented in 

 certain Rhodophyceae (e.g. Dasya, species of Polysiphonia) by 

 specialised branches of the shoot, termed stichidia, which bear 

 gonidangia (tetragonidangia) . 



Turning to the sporophyte, the sporophore in these lower plants 

 is not hig'hly developed. In some few Fungi (e.g. Mucor) it is 

 essentially similar to the gonidiophore ; in other Fungi (e.g. Asco- 

 mycetes) and in certain Algae (Rhodophyceae) the whole sporo- 

 phyte is simply a sporophore in the form of a receptacle contain- 

 ing sporangia ; it is termed in the one case an ascocarp, and in the 

 other a cystocarp. 



The sporophyte of the Muscinese affords a good example of a 

 highly specialised sporophore in an organism the shoot of which 

 is not differentiated into stem and leaf. The entire shoot of the 

 sporophyte constitutes the sporophore, which consists (except in 

 Riccia) of a longer or shorter stalk (seta), bearing a terminal 

 capsule (theca) of more or less complex structure (see p. 71). 



In the majority of the higher plants, in which the shoot of the 

 sporophyte is differentiated into stem and leaf, there are well- 

 marked sporophores (see Fig. 36). The sporophore may be the 

 terminal portion of the primary shoot or of a branch ; or it may 

 be an entire branch. It is commonly known, among Phanerogams, 



