LE maout's botany. 247 



always in plunging into their flowers, rubs against the stigma or summit 

 of the seed-bearing organ. Observe now, it is at the time when the an- 

 thers shed their pollen, that the stigma bedews itself with a viscid mois- 

 ture, and it is also at this time that the nectar is distilled which invites 

 the insects to their repast. Is this coincidence of no importance ? Does 

 it not tempt you to believe that these insects, cotemporaries of the flow- 

 ers, are the grateful messengers, who, to repay the hospitality received, 

 distribute, in the hotel where they next arrive, the pollen collected in 

 that they have just left? 



But what j)urpose is served by the fragrant and painted corolla of 

 the flower ? This expands when the anthers yield their pollen, when 

 the stigma becomes humid, when the nectar is distilled, and when there 

 are insects to drink it. It needs no great sagacity to conclude from this 

 union of circumstances, that the corolla, by its form, its shades, and its 

 odour, is designed to indicate to the insects the reservoir whence they 

 may draw the syrup they love : it is the label upon the vase containing 

 the precious nectar; the invariable uniform of all flowers of the same 

 species, and the insect voyagers readily recognize by its brilliant colors 

 the balmy caravansary where they delight to revel. 



Insects, then, are valuable auxiliaries in the fecundation of flowers, 

 either by transporting the pollen from one plant to another, or by aid- 

 ing in its dispersion upon the stigmas of the same flower : and for this 

 reason it was necessary, in the experiment upon the melon of which we 

 have spoken, to cover the plant with a fine gauze to prevent the access 

 of insects. Without this precaution, pollen might have been carried to 

 a flower which the experimenter wished to be deprived of it, and thus 

 the experiment rendered doubtful. 



We are indebted to Conrad Sprengle, a German, for a knowledge of 

 the part performed by the corolla and the nectar in the history of the 

 flower. This additional link in the great chain that unites the vegetable 

 and animal kingdoms, he discovered by long and close observation. — 

 With a patience truly German lie passed entire days in the fields, couch- 

 ed at the foot of a plant with his eye constantly fixed on the flower, 

 whose anthers were not yet opened-, at length, after a silent and motion- 

 less watch, often prolonged till evening, he saw the aerial messenger ar- 

 rive, whose manoeuvres he was so anxious to observe. The insect, after 

 some preliminary evolutions, plunged into the flower and made its re- 

 past. When it again issued forth, Sprengel saw the grains of pollen ad- 

 hering to the stign;a and returned home contented with his day's labor. 



Since the appearance of the great Linnaens we more frequently meet 

 with these noble enthusiasts in the cause of science to whom sixteen 



