sts,mens of the fused nine : these hy having the cells of 

 their filiaments intensely turgid tend to make the vrhole 

 staroinal tuhe assume a curved form wherehy the stigma and 

 anthers are forced against the vexillum. This explosive 

 force is resisted "by the paired comhining processes of the 

 alae and carina and according to my ohservation not "by 

 the basal process of the alae." 



Burkhill covered a considerahle number of alfalfa 

 flowers with nets to prevent insect visits: no seeds are 

 set he states in the uneKploded flowers. 



Eurkhill states that the stigma does not become 

 receptive until rubbed or until its cells are injured in 

 some manner. He says: "l!y proof is I think conclusive: 

 Firstly, the stigina appears not to be moist, but when 

 rubbed on glass leaves a stickjA mark. Secondly, I have 

 caused flowers to set seed though unexploded, (1) by 

 pinching the stigma through the kell, (2) by perforating 

 the keel with a needle and scratching the stigma, and (3) 

 by cutting off the tip of the keel and rubbing the stigma 

 with a stiff paint brush." 



Burkhill saj'-s that the hive bee does not explode the 

 flower, but inserts its probosis obliquely over the basal 

 processes and not between them. It is necessary to pro- 

 duce explosion for an insect to insert its probosis be- 

 tween these basal processes. 



(66) 



