122 DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



were formed by division from the spore which is the product of the archicarp of 

 Vaucheria, it would be a sporocarp though a sporocarp of very simple form. 



By the term sporocarp we designate bodies originating in the manner just 

 described which serve almost exclusively to the formation of spores, and which cease 

 to exist after having once with comparative rapidity developed a certain number of 

 spores. This is distinctly true of the majority of the illustrative cases adduced above 

 and of the simpler ones also. But here too a gradation of difference may be 

 observed, not only in the number of different successive steps in the development 

 which have to be traversed, but also in the number of repetitions of the same step. 

 Compare in respect to the first point the rapid and simple development of the 

 sporocarp of Riccia with the tedious and complicated development of Polytrichum 

 or even of one of the Jungermannieae ; in respect to the second point compare 

 Riccia with Anthoceros. 



If while other conditions are again the same the differentiation of the sporo- 

 carp is carried beyond the conventionally and traditionally determined limit, 

 the formation of spores is confined to definite comparatively small segments or 

 portions of segments of the body developed from the archicarp; and if the 

 formation of these sporogenous segments is repeated in a periodical succession, which 

 is typically and in most cases also actually unlimited, we cease to use the term 

 sporocarp. We may adopt the word sporophyte or any other suitable and plain 

 expression in its place. This case occurs when we pass from the Mosses to the Ferns 

 and the classes of the Flowering plants arranged in series with them. Here again it 

 is presumed that the facts on which the term sporophyte is based are already known. 

 In the Ferns the leafy sporiferous plant is the sporophyte developed from the 

 archicarp which is the product of the prothallium ; in the Phanerogams the 

 sporophyte is in like manner the entire growth from an oosphere (archicarp), with 

 the exception of the embryo-sacs, each of which is the homologue of a spore and of 

 the products of development other than the embryo which are formed in the sacs 1 . 



In flowering plants the sporophyte and the body from which it originates, 

 the oosphere, are so related to one another as regards their size and position that 

 the oosphere appears to be a small portion of the sporophyte. The opposite is the case 

 in Vaucheria, Fucus. and Chara, where the sporophyte or sporocarp is reduced, so 

 to speak, to a single spore which forms a small portion of its parent. In Ferns, 

 Mosses, Florideae, &c. the relationships of the two bodies are less unequal; both 

 alike appear as special stages of the development which proceed from one another in 

 turn, and it is for this reason that these plants have served as guides in the 

 determination of the morphology of the rest. 



The course of development described above may follow the rule there laid down 

 without any further complication. Instances of this may be seen in Chara crinita, in 

 the apogamous Ferns 2 with some slight limitation which will be noticed hereafter at 

 greater length, and also in Coelebogyne 3 . But these are only isolated exceptions. 

 The almost universal rule, as is well known, is that the development of the 



1 It hardly need be observed that it does not affect the questions with which we are at present 

 concerned, whether the strict homology is between fern-spore and embryo-sac or between mother- 

 cell of the fern-spore and embryo-sac. 



2 See Bot. Ztg. 1878, p. 449. ' Strasburger, Ueber Polyembonie, Jena, 1878. 



