FERTILISATION. 



407 



oosphere is exactly the same as in Monotropa and Orchis (B, C). 

 In the synergidae the nuclei lie in the upper, the vacuole in the 

 lower part ; in the oosphere this is reversed. 



If we wish to study the process of fertilisation in Torenia 

 we must pollinate the flowers for the purpose. From pollination 

 to fertilisation about thirty-six hours elapse, so that we must 

 renew our observations after from a day and a half to two days. 

 As before, we free the ovules from the placenta, but as carefully 

 as possible, under the simple microscope, in order to remove the 



