Meyen's Report for 1839 on Physiological Botany, 467 



M. Braun * has also communicated his ideas on the growth 

 of the OphioglossecE, particularly with regard to the cellular 

 body from which the leaves are produced. This body is said 

 to surround the centre of formation^ and within it the leaves 

 are produced in regular spiral succession until they unfold, 

 which they do in the fourth year in the case of Oph, vulgatum. 

 The spike oiOphioglossum is axillary. Botrychium does not pos- 

 sess this inclosing cellular body, but the leaves have a sheath. 



In the Report of 1837t5 the observation of M. Martens was 

 mentioned, according to which hybrid forms are found among 

 the Ferns ; the new hybrid which M. Martens has observed, 

 was called by Bory de St. Vincent Gymnogramma Martensii, 

 and was said to be intermediate between G. calomelanos and 

 G.chrysophylla. Mr. J. Riley J of Nottingham has made an 

 excellent reply to this assumption of M. Martens, although 

 he appears not to know that many botanists believe that the 

 anthers of Ferns have been discovered, a subject which was 

 discussed in the former Report, 1836, p. 104. Mr. Riley con- 

 siders this supposed hybrid as G. sulphurea, Desv., and gives 

 very sufficient reasons for supposing the formation of hybrids 

 in the Ferns as altogether improbable. 



Mr. G. Dickie § has published some remarks on the appear- 

 ance of amylum in plants ; he notices particularly that in the 

 Lichens ; but it was unknown to him that many decisive ob- 

 servations have been already made on this subject. Mr. Dickie 

 assumes that all those parts of Lichens which are coloured 

 blue by iodine are amylum, and he found that even the spo- 

 rangia (thecae) are coloured blue; he compares the sporangium, 

 with the spores which are produced therein, with the structure 

 of the amylum globules ; this however is founded on Raspail's 

 description of the structure of Amylum, w^hich is erroneous. 



M. G. Korber|| has chosen as the subject for his inaugural 

 dissertation a very circumstantial description of the green cells 

 of the thallus of Lichens ; these are the peculiar cells which 

 Wallroth calls gonidia, and Meyer germinal grains. 



The author has given the various statements of the two 

 above-mentioned lichenologists with all possible brevity and 

 clearness, has criticized them, and sometimes added his own 

 views, which are grounded on observations of nature. The 

 gonidia were observed in three different stages : 1. as gonidia 



* Florca von 1839, p. 301. 



t See Mr. Francis's translation : London, R. and J. E. Taylor, 1839, p. 81. 

 X Reply to M. Martens's Paper on the Hybridity of Ferns. Proc. of the 

 Bot. Soc. of London, 1 839, p. GO. 



§ Annals of Nat. Hist. 1839, p. 165. 

 II De Gonidiis Lichenum. Diss. Inaug. Berolini, 1839. 



2 H 2 



