THE HIGHER CRYPTOGAMIA. 123 



Many of the most interesting specialities are to be found in 

 Gottsche's two writings above referred to. The above 

 investigations of Mirbel and BischofT are so generally 

 studied and known that it would be superfluous to give 

 even a short summary of the valuable results obtained by 

 them. Good representations of the fruit and perianth of 

 Marchantia polpnorpha are to be found in Micheli's ' Gen. 

 PI./ p. 2, and in Dillenius's ' Hist. Mnsc.', pi. xxviii, 

 figs, m, n, who also figures the germination of the 'gemmae. 

 Micheli considered the male and female plants as different 

 species ; the relation of the two was first noticed by 

 Kupp ('Flora Jenensis/ ii, 276), then by Dillenius (1. c, 

 p. 524), and with certainty by Linnaeus (SP. PL. 1137). 

 Our present more accurate knowledge of the Marchantieae 

 dates from the publication of Schmidel's observations 

 ('Icones pi./ ed. ii, p. 109 M. jpolymorplia ; p. 120 Fega- 

 tella conica; p. 133 Preissia commutata) . Schmidel 

 isolated the antheridia, and pointed out their mode of attach- 

 ment to the tissue supporting them ; he gave an accurate 

 figure of the structure of the receptacle, and described the 

 spontaneous detachment of the fruit- stalk of Fegatella conica 

 from the tissue of the mother-plant. Hedwig (' Theoria 

 generationis/ ed. ii, 1798) distinguished the enveloping 

 cellular layer of the antheridia (p. 176), and found that 

 in the young fruit the young perianth did not reach 

 to the height of the mouth of the archegonium (p. 177). 



The object of Mirbel, in his remarkable work on Mar- 

 chantia polymorpha ('Mem. Acad. des. Sciences de Tlnst. 

 de France/ xiii, 1835) was to investigate fully the 

 history of the development of this plant in all its speciali- 

 ties. This object was only imperfectly attained. Mirbel 

 observed the germination of the spores. He came, how- 

 ever, to the erroneous conclusion that the newly added 

 cells were produced on the outside of the existing cells 

 (I.e., p. 347). This error arose from the circumstance 

 that in young multicellular germ -plants which are fur- 

 nished with only one rootlet, the cell out of which the root- 

 let is formed is very similar in shape and size to the 

 germinating spore, whilst the latter is still unicellular, but 

 w 7 hen it has already developed a rootlet. His view of 



