Tilden: MORPHOLOGY of hepatic ELATERS. 45 



and the cell membrane, which until this time has surrounded 

 them, dissolves so that finally the spiral band alone is left. 

 These bands are very elastic, and it is by means of them that 

 the sporogonium is opened. On staining with iodine and sul- 

 phuric acid they becon^e first yellow, then red and at last green. 

 They appear, therefore, to be composed of a mixture of muci- 

 laginous and protein substances." Leitgeb also takes up this 

 question quite exhaustively through the different genera. 

 Blasia pusilla^'' is described as having generally two-spiraled 

 elaters. But near the middle of the cell each (or only one) of 

 these spirals divides into two branches which run along paral- 

 lel to each other. So that in the middle of the elater cell four 

 (or three) separate fibres run beside one another. Sometimes 

 one of these branches becomes split again, so that frequently 

 three pairs of spiral bands are observed. Again he states that 

 the elaters of Blyttia^^ possess two spiral bands; those of Petal- 

 ophyllurn}^ have mostly two, light-colored, small spiral bands; 

 and those of Cyathodium in most cases have three spirals. ~o He 

 shows a figure of one-spiraled and annular elaters of Boschia.-^ 



Underwood states that in rare cases elaters contain annular 

 bands.-- Schiffner specifies that the elaters of Bazzania pecti- 

 nata had two spiral bands present but that he was unable to 

 find any trace of cell wall.'^^ jje also gives a figure of an elater 

 of Anthoceros grandts which has but one spiral baud. 04 



The origin and development of the elater cells has been taken 

 up in detail by Schacht.^s Hofmeister describes the method of 

 development of elaters in Pellia epiphylla,-^ and in Targionia-'^ 

 likens the arrangement of elaters and spore mother-cells to 

 that of the chlorophyllose and vesicular cells in the leaf of 

 Sphagnum. Leitgeb-^ mentions elater-like cells with irregu- 

 larly thickened bands found on the bottom of the capsule in the 

 Marchantiacece, and believes them probably to be rudimentary 

 elaters. On another page he describes the method of forma- 



17. Leitgeb Untersuch. u. d. Lebermoosc, 1:51. 1874. 



18. Leitgeb, loc. cit. Heft. III. 85. 1874. 



19. Leitgeb, loc. cit. Heft. III. 133. 1874. 



20. Leitgeb, loc. cit. Heft. VI. 138. 1879. 



21. Leitgeb, loc. cit. Hefi IV. Taf. VI. fig IP. 1879. 



22. Underwood. Bull. Illinois Lab. Nat. Hi.st. «: 11. 1884. 



23. Schirtrier, Ueber e.\ot. Hep. 260. 1893. 



24. Schiflner, loc. cit. Taf. Vi. 



25. Schacnt, Beitr. z. Entw.-Ges. d. Frucht n. Spore v. Anthoceros laevis. Bot. Zeit. 

 8 : 489, 28 Je. Taf. VI. fig. .52. 1850. 



26. Hofmeister, Vergl. Untersuch. d. Keini. Entw. u. Frucht. Hoherer Krypt. 20. 1851. 



27. Hofmeister, loc. cit. 58. 1851. 



36. Leitgeb, loc. cit. Heft VI. 44. 1879. 



