THE FERTILIZATION AND DEVELOPMENT OF FLOKIDEJE. 449 



Schmitz the fusion is confined to the two masses of protoplasm, 

 while the nuclei remain separate ; but from his writings and 

 drawings it can be seen that he overlooked the auxiliary nucleus 

 m later stages and confused it with that of the sporogeuous- 

 filaments. 



The next plant examined in the same minute manner is 

 Dudresnmja coccinea. The general development of the fruit is well- 

 known, but the behaviour of the nuclei is here clearly explained 

 for the first time. It differs from that of D. purpiirifera in several 

 details, such as the division of the auxiliary-cell nuclei, which does 

 not occur in D. purpurifera. The same extraordinary influence 

 however appears to be exercised in these auxiliary nuclei, by the 

 sporogenous nucleus, for both auxiliary nuclei are found after fusion, 

 even mdeed in the oldest cystocarps, closely pressed together and 

 hardly movmg from their position at the far end of the cell. The 

 auxihary nuclei in D. coccinea do not diminish in size as in Z). 

 purpurifera. The formation of the " gonimo-lobes " is described! 

 The sporogenous nucleus divides twice to form the two lobes, but 

 though there always remains a sporogenous nucleus in the auxiliary- 

 cell which bears, and gives rise to, these two gonimo-lobes, Prof. 

 Oltmanns has never seen more than two lobes in each fruit. 



This is more or less the same result at which Prof. Schmitz 

 arrived, but his description of the behaviour of the nuclei was not 

 clear, and it may be doubted if he had fully grasped the details of 

 the subject. 



The next plant examined by Prof. Oltmanns is Glceosiphonia 

 capillaris, of which Prof. Schmitz wrote: " It may well be main- 

 tained that the nucleus of the ooblastema-cell fuses with that of the 

 auxihary-cell, since after the emptying of the ooblastema-cell only 

 a single nucleus is present in the auxiliary-cell." Prof. Oltmanns 

 shows that this statement is incorrect. After fusion of the sporo- 

 genous-filament and the auxihary-cell, the auxiliary nucleus divides 

 mto two, and these two sister-nuclei move later towards the centre 

 of the fused cell, where they may be found close to the sporogenous 

 nucleus. Thus in every case there are at least two nuclei in the 

 cell which results from the fusion of the sporogenous-filament and 

 auxihary-cell. The only instance of a single nucleus being found 

 in an auxihary-cell, after contact with the sporogenous-filament is 

 after so-called '' blind fusion," where the sporogenous nucleus does 

 not enter the auxiliary-cell, and consequently no further develop- 

 ment or growth takes place. This has been seen by Prof. Oltmanns 

 in Dudresnaya and Glceosiphonia. In such cases the contents of 

 the auxihary-cell nucleus are denser than usual, and the sporo- 

 genous-filament after leaving the auxihary-cell is as a rule much 

 branched. 



Prof. Oltmanns maintains with decision that in Glceosiphonia, 

 as m Dudresnaya, there is absolutely nothing to justify the theory 

 of a second act of fertihzation, so far as fusion of nuclei goes. 



An interesting point occurs in connection with the outgrowth 

 of tlie auxihary-cell after fusion with the sporogenous-filament. 

 in Dudresnaya this cell begins to swell out at the point where the 



