i $8 COLIN CLOUT'S CALENDAR. 



claws in order to let him get more easily at the mouth 

 of the tube. In the common scarlet species all the 

 petals are coloured much alike : but in these rarer kinds 

 that grow by its side the irregularity is much more 

 marked ; for the lower three are uniform in hue, while 

 the upper pair are striped with darker lines, which lead 

 straight to the opening of the nectary, thus acting as 

 regular honey-guides. 



Much the same thing happens in the nasturtium ; 

 which, however, is far more remotely allied to the true 

 geraniums, and which probably arrived at its own similar 

 arrangement by a distinct line of evolution. Whether 

 the honey-tube of the pelargonium was once separate 

 from the stalk, as that of the nasturtium still is, and 

 whether it afterwards coalesced with it, it would be 

 difficult to decide. Certainly there would be a slight 

 gain in the latter plan, as I have often seen humble-bees 

 unable to get at the honey of the nasturtium in a lawful 

 fashion owing to the length of the tube (which is not 

 well adapted to any British insect), feloniously appro- 

 priate it by biting through the side in which case, of 

 course, they cannot benefit the plant, as they do not 

 touch the pollen or fertilise the seeds ; while I have 

 never observed anything of the sort happen in a pelar- 

 gonium, where the honey is much better concealed. It 

 is more likely, however, that the spur in this last instance 

 has really grown out of a slight depression along the 

 footstalk ; and, if so, it can never have been a single 

 separate organ. 



