9 



tubes; to some extent this is probably a resuit of the 

 process of fixation, during wbich such tender, thin struc- 

 tures readily shrivel up; at the same time the staining 

 does not succeed well. In any case I can however state, 

 that the pollen-tube pénétrâtes through the micropyle, 

 and then reaches the egg-apparatus by passing between 

 two epidermal cells of the nucellus (fig. 9). In one case 

 I observed two nuclei In the top of the pollen-tube, one 

 of which appeared to be a generative and the other a 

 tube-nucleus. In another case I saw a nucleus, which 

 had a much elongated appearance, and was constricted 

 in the middle, so that there might hâve equally well 

 been two generative nuclei. Taking ail the cases, which 

 I hâve seen, into account, I am led to the view, that the 

 conditions in the top of the pollen-tube are normal, so 

 that there are two generative nuclei and one tube-nucleus. 

 In the actual process of fertilisation, the top of the pol- 

 len-tube unités with one of the synergids; the synergid 

 and especially also the egg undergo at the same time 

 peculiar changes in shape, somewhat resembling amoeboid 

 movements. What further happons in the synergid cannot 

 readily be made out, because its contents stain very 

 strongly and become highly refractive. I nevertheless also 

 succeeded in this case in observing the main features of 

 the process. At least one nucleus of the pollen-tube péné- 

 trâtes into the synergid and assumes, in so doing, a 

 more or less vermiform shape. Thereupon a fusion ofthe 

 synergid with the egg takes place (flg. 9), so that the 

 protoplasts communicate with each other at least at one 

 spot. This communication does not last long, but during 

 it one of the generative nuclei evidently pénétrâtes into 

 the egg-cell; anyhow stages are found later, in which 

 two nuclei lie close to each other in the egg. Still a little later 

 thèse are found in contact, and afterwards they are found 



