436 HABITS OF INSECTS. Chap. XI. 



by alighting on the upper surface of the corolla 

 and sucking through the cut holes, as by entering 

 in the proper way. Nevertheless each bee before 

 it has had much practice, must lose some time in 

 making each new perforation, especially when the per- 

 foration has to be made through both calyx and 

 corolla. This action therefore implies foresight, of 

 which faculty we have abundant evidence in their 

 building operations ; and may we not further believe 

 that some trace of their social instinct, that is, of 

 working for the good of other members of the com- 

 munity, may here likewise play a part ? 



Many years ago I was struck with the fact that 

 humble-bees as a general rule perforate flowers only 

 when these grow in large numbers near together. In 

 a garden where there were some very large beds of 

 Stachys coccinea and of Pentstemon argutus, every single 

 flower was perforated, but I found two plants of the 

 former species growing quite separate with their petals 

 much scratched, showing that they had been frequently 

 visited by bees, and yet not a single flower was 

 perforated. I found also a separate plant of the 

 Pentstemon, and saw bees entering the mouth of the 

 corolla, and not a single flower had been perforated. In 

 the following year (1842) I visited the same garden 

 several times : on the 19th of July humble-bees were 

 sucking the flowers of Stachys coccinea and Salvia 

 grahami in the proper manner, and none of the corollas 

 were perforated. On the 7th of August all the flowers 

 were perforated, even those on some few plants of the 

 Salvia which grew at a little distance from the great 

 bed. On the 21st of August only a few flowers on the 

 summits of the spikes of both species remained fresh, 

 and not one of these was now bored. Again, in my own 

 garden every plant in several rows of the common bean 



