REVUE BRYOLOGIQUE // 



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though they are described by Lcitgeb and by Ruge as being spi- 

 rally twisted. 



The writer has not vet been able to follow in detail the devo- 



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lopment of the sporogonh m^ bnt from tlie stages observed it 

 appears that in this respect Monoclea resembles the Marchan- 

 tiacea} rather tlian the typical Jungermanniaca^. Tlie first wall 

 formed in the fertilised egg-cell is transverse, and it is followed 

 by a transverse division in the upper cell. The lower (hypobasal) 

 cell gives rise to the foot, the superficial cells of which soon pro- 

 ject as rounded papillae, whilst the two upper cells immediately 

 divide by vertical walls and give rise to the capsule and seta. In 

 one case, the basal wall had been immediately followed by 

 vertical divisions in both cells, giving a regular octant stage, as 

 in the Marchantiacea? (Fig. 4, C). 



In most of the plants examined by the writer each involucre 

 contained a single sporogonium, enclosed in a fairly thick calyp- 

 tra(coifl'e) which carried unfertilised archegonia and mucilage-hairs 

 on its sides, especially near the base (Fig. 4, A.). In some fruiting 

 plants observed by Mr. AYebslcr, and recently sent by him to the 

 writer, some of the involucres conlhin twosporogonia (Fig. 1. C.) ; 

 this agrees with the account given by Stephani,* who slates that 

 that tlie fruits often occur in pairs. 



The ripe capsule is long and cylindrical (about 7 mm. X - nim.) 

 and is dark brown in colour. Tlie seta, which ends below in a 

 small bulbous foot, attains a length of about o cm. when fully 

 rown ; for about a third of this length it is enclosed in the tubu- 



if 



lar involucre. The wall of the capsule consist of a single layer of 

 cells (not of two layers, as stated by Scliiffiiert) ; these cells are 

 large and oblong in form, having a narrow rectangular outline in 

 a transverse section of the capsule (Fig. 4. F.). Each cell has its 

 outer and inner walls uniformly thickened, but the radial walls 

 bear each numerous (8-12) fibres, which run obliquely across the 

 wall and lie lor the most part parallel with each other, but some- 

 times branch and anastomose. Moreover, the two sets of fibres 

 on opposite sides of a wall cross each other, giving a reticulate 

 appearance in a longitudinal section of the capsule (Fig. 4, G.). 



The capsule opens by a single longitudinal .slit which com- 

 mences at the apex of the capsule. This slit is not constant in 

 position, nor does the ripe capsule bend forwards so as to lie 

 horizonlally, as one would gather from the original description 



* F.oc. cil.. p. 352. 



t Engler u. Prantl, Nat, Pllanzenfam., Hepaticoe (1893), p. 56. 



