56 



Crossing is not an absolute necessity with plants. Not 

 only do many appear quite indifferent, but in some 

 instances, marvellous as it may seem, special provision is 

 made to prevent crossing. Some Violets only produce fer- 

 tile seed in flowers that do not open and whose ovules can 

 only be fertilised by their own pollen. The same often 

 occurs in one of our Hibbertias. Further, in the enormous 

 class of Fungi, in which there are already forty thousand 

 described species, fertilisation of any sort is seldom known, 

 yet they go on for generation to generation living their 

 lives and doing their work, quite indifferent to the per- 

 fection of their celibacy. 



