ISO 



MORPHOLOG Y. 



falling here and there. It appears also as if there were twisting 

 threads which aided the spores in becoming freed from the 

 capsule. 



Fig. 182. 

 Section of archegonial receptacle of Marchantia polymorpha; ripe 

 sporogonia. One is open, scattering spores and elaters ; two are 

 still enclosed in the wall of the archegonium. The junction of the 

 stalk of the sporogonium with the receptacle is the point of attach- 

 ment of the sporophyte of marchantia with the gametophyte. 



321. Spores and elaters. — If we take a bit 

 of this mass of spores and mount it in water 

 for examination with the microscope, we will 

 see that, besides the spores, there are very 

 peculiar thread-like bodies, 

 the markings of which remind 

 one of a twisted rope. These 

 are very long cells from the 

 inner part of the spore-case, 

 and their walls 

 are marked by spi - 

 ral thickenings. 

 This causes them 

 in drying, and also 

 when they absorb 



1 . Fig. 183. 



moisture, to twist Elater and spore of marchantia. sp, spore ; 111c, mother-cell of 

 . , ,, spores, showing partly formed spores. 



and curl in all 



sorts of ways. They thus aid in pushing the spores out of the 



capsule as it is drying. 



322. Sporophyte of marchantia compared with riccia. — 



We must recollect that the sporogonium in marchantia is larger 

 than in riccia, and that it is also not lying in the tissue of the 

 thallus, but is only attached to it at one side by a slender stalk, 



