( 687 ) 



must be looked upon as an embiyo, the development of which has 

 already for some time been stopped and which is now in progress 

 of disorganisation. Also here nothing peculiar was further found 

 in the embrjosac. 



Of course we looked also for the presence of an egg-apparatus, 

 especially in the younger stages, but there is only one preparation 

 in which anything of this kind can be detected. It is an ovule, 

 collected on August 22, where in the top of the embryosac three 

 cells are found, two shorter ones with distinct nuclei and a third 

 which is larger with disorganised cell-contents in which the nucleus 

 can still be discovered, however. We believe this to he the egg, 

 the others synergids. Here also nothing else is found in the embiyosac 

 except protoplasm, which stains strongly. 



In 10 other ovules an endosperm was observed in various stages 

 of development. It must be stated at once that in none of these 

 anything of the nature of an embryo is seen. Although it may be 

 objected that for some ovules the series of sections is not complete, 

 yet this is certainly not the case with the majority. Especially where 

 the micropyle is seen in the section, the embryo would be sure to 

 be observed if it were there, but also in this case no trace of it 

 can be found. So we arrive at the conclusion that here an endosperm 

 has been formed without the embryo having developed. 



An ovule, collected on August 15, shows the smallest quantity 

 of endosperm. The upper part ('/, to 74) of the embryosac is füled 

 up with it. The shape of the embryosac has been changed ; it is 

 swollen, has become cylindrical or somewhat broader towards the 

 bottom, has a thickness of 0,4 mm., while the nucellus has a 

 maximum diameter of 1,0 mm. The lower part of the embryosac in 

 which no endosperm is found, has entirely collapsed and has evidently 

 been squeezed by the surrounding cells. This same shape of the 

 embryosac was met with only once without an endosperm having 

 been formed in it, namely in an ovule, collected on the same day. 

 " In the lining protoplasmatic layer no nuclei could be seen, but still 

 we believe that this was a first beginning of the formation of an 

 endosperm. Now the endosperm of the just-mentioned ovule consists 

 of thin-walled cells of varying size; normal nuclear divisions occur 

 but also nuclei of abnormal size with a number of nucleoli, indicating 

 fragmentation. At one of the sides of the embryosac the formation 

 of the endosperm has not yet been completed. 



Curiously enough the next stage in the development of the endos- 

 perm was observed with an ovule, fixed on December 15. Here the 

 greater part of the tissue of the nucellus has been displaced, so that 



