298 M. A. Brauu on the Nucleus of the Characese. 



BischoflF in the year 1828*, who at that time regarded them as 

 Infusoria. Varley (1834) first saw their exit from the cells of 

 the antlicridial filaments ; but the two most delicate cilia, by the 

 vibration of which the spirally wound body is set in motion, were 

 first described by Thuret in the year 1840t. Thuret saw these 

 cilia in Nitella syncarpa and Chara fragilis ; I have seen them so 

 distinctly in Chara aspera and ceratophylla, that no doubt what- 

 ever can exist as to their pi-esence. I have only to add to Thu- 

 ret's account, that I have found the winding of the spiral body 

 constant to the right in Ch. fragilis. The second organ of fruc- 

 tification, in which the spore is developed, regarded by the older 

 botanists as a pistil, and in the ripe condition called either 

 ■ capsule (Vaillant), berry (Sprengel, Willdenow), drupe (Berto- 

 loni), or nucule (Wallroth), or merely seed (Linnaeus), has been 

 subsequently, quite as unfitly, termed a spore-case, sporocarp (Bis- 

 chofi"), or sporangium (Cosson and Germain). Hofmeister com- 

 pares it with the archegonium {pistillidium) . Apt as this compa- 

 rison seems in reference to the reduction of the characters of 

 fructification of all the higher (sperm atozoid-bearing) Crypto- 

 gamia under one common point of view, since in this Avay all the 

 plants with unequivocal antheridia likewise possess an archego- 

 nium, peculiar difficulties are met with in the attempt to carry 

 out the parallel. That which has been called an archegonium, 

 is an organ of the first generation of the leafy Cryptogamia, the 

 generation growing up from the spore, in which organ, accord- 

 ing to the researches so profoundly follow^ed out by Hofmeister 

 in ])articular, the germ-cell of the second generation is produced 

 by free cell-formation, and developed after impi'egnation (like the 

 embryo of the Phanerogamia) . In the Vascular Cryptogamia 

 (Ferns, Equiseta, &c.) the first generation consists of a leafless, 

 thalloid preparatory structure, the pro-embryo or prothallium, 

 while the second generation is developed into the leaf-producing 

 ' stock,^ the vegetative, and finally spore-bearing plant ; in the 

 Mosses, on the other hand, the first generation advances from 

 the thalloid preparatory structure to the leaf-producing ' stock,' 

 while the second generation is represented by a peculiar fruit- 

 structure serving merely for the production of the spores, and 

 this structure, emerging from the cavity of the archegonium, 

 sometimes breaks through the cover [calyptra] formed by the 

 latter, and sometimes carries it up through its becoming detached 

 below. In the lowest groups of Ilepaticse, especially in the 

 Ricciea, this fruit-structure, so complicated in the higher Mosses, 



* Crypt. Gevviichse, p. 13, in the note. 



t Ann. des So. Nat. 2nd ser. xiv. (1840), p. 65 ; and 3rd se'r. xvi. (1851 ), 

 t. 9. 



