Higher Cryptogamia and the Phanerogamia. 455 



the latter transitory. Moreover we have the two forms here existing 

 contemporaneously, the prothallium or fruit-form constituting the 

 vegetative structure which nourishes the spore-bearing form, 

 here reduced to a sporocarp ; while in the higher forms the pro- 

 thallium disappears soon after it gives birth to the leafy spore- 

 bearing plant. 



The spore of the Mosses and Hepaticse represents the spore of 

 the Ferns, the large and small spores (combined) of the Lyco- 

 podiums and Rhizocarpese, and a combination of the pollen and 

 embryo-sac of the Gymnosperins*. "When it germinates it pro- 

 duces the leafy plant, representing the prothallium of the higher 

 Cryptogamia and the endospermous tissue of the Gymnosperms 

 (and Angiosperms), and bearing antheridia and archegonia. The 

 archegonia then produce the spore-fruits, which represent the 

 fertile fronds of the Fern, the spikes of Equisetum, the sporo- 

 carps (collectively) of the Lycopodiacese and Rhizocarpese, and, 

 lastly, the anthers and ovaries of flowering plants. Therefore in 

 the Mosses we have nothing homologous with the stem and 

 leaves of the higher Cryptogams and flowering plants in this 

 spore-bearing form ; these are only developed in the prothallium- 

 formf- 



Looking at the more perfect Mosses alone, this idea of the 

 morphological relations of the leafy Moss-plant, of the prothal- 

 lium, namely, to the endosperm of Phanerogamia, seems rather 

 difficult to accept ; but when we examine more closely into the 

 various forms included under the families of Mosses and Hepa- 

 ticse, it becomes less remarkable. The separation of these two 

 groups is by no means natural. There are no essential differ- 

 ences in the antheridia and archegonia of the Mosses and Hepa- 

 ticse, and in the fully developed condition of their spore-bearing 

 structures there is no universal character which will separate 

 them. Many of the leafy Jungermannia have the Confervoid de- 

 velopment of the prothallium from the spore ; the Jungermanniee 

 have a vaginule, as also Radula and Anthocei-os ; this last has a 

 columella, but like Riccia it is destitute of elaters. So that if 

 with Hofmeister we divide the plants belonging to these two 

 families into four groups, — 1. Mosses; 2. Jungermannise ; 3. 

 Marchautiae, Targionese and Ricciese, and 4. Anthocerotese, — they 

 collectively form quite as natural a family as the Ferns or Rhi- 

 zocarpese. Then looking to the lower forms of this family, we 



* Since some Mosses are dioecious, the sexual influence is represented 

 even in the spores ; some are embryo-sac spores, others pollen-spores ; but 

 both kinds produce a prothallium. 



t There is also a further separation of existences in the Mosses and 

 some Hepaticce, for the spore produces a Confervoid body from which se- 

 veral stems bud out ; this resembles the polyerabryony of Gymnosperms. 



