cmd Development of Manilea. 419 



at the same time being divided again by a septum directed from 

 without inwards towards the common point of contact of all the 

 four. By the further elevation of the four upper daughter cells 

 the neck of the archegonium is completed. 



At about twenty to twenty-four hours after the escape of the 

 spores, the archegonium is ready for impregnation ; and fer- 

 tilization takes place without being limited to any particular 

 time of the day*. Beneath the vertex of the central cell a 

 portion of colourless mucus separates from its yellowish mass of 

 protoplasm, and fills a somewhat lentiform space below the neck 

 of the archegonium, which frequently appears to be divided by 

 sharp boundary lines from the contracted globular protoplasmf. 

 This mucus swells, presses upwards, bursts out suddenly with a 

 violent explosion between the four pairs of cells of the archego- 

 nium, and thus opens the canal of its neck, which then leads 

 from without into the interior of the central cell. The mass 

 thrown out often remains for days unchanged near the orifice. 



Of the swarming spermatozoids many are usually already at 

 hand. They do not seek after the entrance in the mucous en- 

 velope of the gynospore, but penetrate it where they come upon 

 it. In this process the starch-saccule is an obstacle ; by ener- 

 getic whirlings they get rid of it, and then swim to the orifice 

 of the archegonium, usually with the apex of the screw in 

 front, and then, as before, very rapidly, or in the reversed posi- 

 tion, and then more slowly. 



Immediately after the expulsion of the mucus, I saw a sper- 

 matozoid hasten by, turn the apex of the screw into the orifice, 

 turn rapidly upon its axis for a moment, as if it had to overcome 

 some internal resistance, and then suddenly disappear in the 

 interior of the archegonium, where it was impossible to trace it 

 further, on account of the opacity of the prothallium. In one 

 case two disaj)peared, one after the other, in the same archego- 

 nium. All subsequent ones were rejected, although no hindrance 

 to their admission was observable. 



The number of spermatozoids which collect in the mucous 

 envelo|)e of a gynospore often amounts to several hundreds. 

 Whole tufts of them adhere by their points to the orifices of the 

 fertilized archegonia, the necks of which quickly become brown.^ 

 About the unfecundated specimens those little swarming cor- 

 puscles whirl' T '"'rnierly mentioned J soon occur. But I have 



• I have witnessed the swarming of the spermatozoids even about mid- 

 night. 



t The precise observation of the processes of material change within 

 the central cell is prevented by the imperfect transparency of the pro- 

 thallium. 



X Monatsber. Berl. Akad. 1862, p. 114 



27* 



