Bramble-Dwellers 



symmetry was most striking. And observe 

 that this was not an effect obtained by repeated 

 attempts, by haphazard experiments. Each 

 Osmia in the left half had bored to the left, 

 without touching the partition on the right; 

 each Osmia in the right half had bored to the 

 right, without touching the partition on the 

 left. The shape of the orifices and the sur- 

 face condition of the partition showed this, 

 if proof were necessary. There had been a 

 spontaneous decision, one half in favour of 

 the exit on the left, one half in favour of 

 that on the right. 



The arrangement presents another merit, 

 one superior to that of symmetry: it has the 

 merit of corresponding with the minimum ex- 

 penditure of force. To admit of the exit of 

 the whole series, if the string consists of n 

 cells, there are originally n partitions to be 

 perforated. There might even be one more, 

 owing to a complication which I disregard. 

 There are, I say, at least n partitions to be 

 perforated. Whether each Osmia pierces her 

 own, or whether the same Osmia pierces sev- 

 eral, thus relieving her neighbours, does not 

 matter to us: the sum total of the force ex- 

 pended by the string of Bees will be in pro- 



44 



