and its relation to that in the Animal Kingdom, 347 



round a secondary nucleus (the rudiment of the future capsule) 

 before the time when the canal opens at the top. Pringsheim* 

 states that he could not convince himself of the presence of this 

 cell before fecundation. 



The majority of the archegonia are arrested at this stage 

 of development. In the rest^ as Hofmeister has shown, and as 

 Valentine t likewise had previously described, there originates 

 from the last-mentioned free cell, by repeated division and the 

 enlargement of the newly produced cells, a more or less fusiform 

 cellular mass (formerly described as a ^ nucleus,^ and regarded as 

 an integral part of the archegonium — and so even by Schacht J), 

 lying free in the simultaneously expanding cavity of the original 

 central cell, its lower end penetrating, in its further growth, into 

 the base of the archegonium, and becoming intimately con- 

 nected with the surrounding structures through the products 

 of solution of the cells which it here displaces. The arche- 

 gonium being no longer capable of withstanding its continued 

 vertical extension, becomes circularly torn at the bottom, and 

 its upper fragment is carried up by the young capsule as the 

 calyptra, while the remnant remains as the vaginuta^. I need 

 not further describe the development of the lower part of the 

 cellular body into the seta {pedunculus) , and of the upper into 

 the theca [capsula), still less the formation of the spores through 

 quaternary cell-division in mother-cells which are arranged in 

 one or more layers. It is equally unnecessary to discuss here 

 the analogies between this and the formation of pollen in the 

 Phanerogamia||. The spore-capsules of the Marchantiece and of 



* Pringsheim, Ueb. Befrucht. u. Keimung der Algen, &c. Monatsber. 

 Berlin. Acad. 1856, p. 15. 



t W. Valentine (Trans. Linn. Soc. of London, xvii. p. 466, read May 

 7th and June 18th, 1833) had already described a free cell at the bottom 

 of the archegonium, and assures us that he had succeeded in dissecting it 

 out uninjured. See also his figures, pi. 23. figs. 1-7, and the explanation, 

 p. 482. — H. Philibert hkewise detected a free cell (* embryo-cell') before 

 fecundation in the central cell of the archegonium (which he called the 

 * embryo-sac') both in Mosses and Liverworts, and in the Ferns. Comptes 

 Rendus, 1852, p. 851 ; Ann. Nat. Hist. 2nd ser. xi. p. 482 (1853). 



X Bot. Zeitung, 1850, p. 459. pi. 6. figs. 1-4. 



§ Vide Hofmeister, I. c. supra ; and on the structure of the ripe capsule, 

 Lantzius-Beninger, Nova Acta, xxii. pt. 1 ; and Schimper, Recherch. sur 

 les Mousses, &c. Strasburg, 1848. 



[I See hereon — 



V. Mohl, Ueb.'Entw. d. Sporen von Anthoceros Icevis. Verm. Schr. p. 84, 

 and Einig. Bemerk. iib. d. Entw. u. Bau der Sporen der Crypt. Gewachse, 

 id. op. p. ^T. 



Lantzius-Beninga, De Evolutioue Sporid. in Capsul. Muscorum. Get- 

 ting. 1844. 



Schacht, Beitr. z. Entwick. d. Frucht u. Sporen v. Anthoceros ItBvis^ 

 Bot. Zeit. 1850, p. 467. 



