150 COLIN CLOUT'S CALENDAR. 



correct! y, only those which did so have ultimately sur- 

 vived. 



Instead of having five honey -glands on an open disk, 

 which any small insects could easily thieve, the pelargo- 

 niums have secreted all their honey in one depression, 

 which has grown longer and longer till at length it has 

 assumed the shape of a deep pouch. This, on the one 

 hand, has made it accessible only to insects with a very 

 long proboscis ; while, on the other hand, it has simulta- 

 neously enabled the flower to make more sure of proper 

 fertilization, and so to dispense with half its original com- 

 plement of stamens. The sensitive surface of the pistil 

 now turns down to meet the pollen on the insect's head, 

 as it poises on level wings before the deep nectary ; and 

 this surface itself consists of five spreading fingers, cov- 

 ered (under a slight magnifying power) with beautiful 

 crystalline glands to which the pollen readily adheres. 

 The irregularity in the petals follows as a guide to the 

 insect ; the upper pair being slightly raised on claws in 

 order to let him get more easily at the mouth of the 

 tube. In the common scarlet species all the petals are 

 colored 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 afterward coalesced with it, it would be diffi- 



