GLASGOW SOCIETY OF FIELD NATURALISTS. 115 



In Viola tricolor (Fig. 12, 13), or Common Violet, the corolla is 

 irregular and composed of five petals. Upon each petal we see 

 certain lines directed to the more or less conspicuous centre of the 

 flower which contains the organs of reproduction. The anthers of 

 the stamens are all vinited together, but if separated or disturbed 

 immediately discharge a shower of pollen. The lower petal is 

 spurred, and contains two tail-like processes (a). These processes 

 are the prolonged connectives of the two lower stamens, which secrete 

 nectar for the purpose of attracting insects. The pistil has a two- 

 lipped hooded stigma (b), the upper surface of which is viscid for the 

 application of pollen. By referring to Fig. 1 2 the mechanism will 

 be better understood. Suppose an insect were to alight upon the 

 lower petal (c) it would be guided to the entrance to the reproduc- 

 tive organs by the streaks upon the corolla. Inserting its proboscis 

 down the spur upon the lower petal in search of honey, it would 

 disturb the anthers, upon sucking the nectar from the connectives 

 a shower of pollen would then fall upon the proboscis of the insect. 

 The insect, on withdrawing its proboscis, will come in contact 

 with the stigma, but as the viscid surface is uppermost, and as 

 there is a protecting lip, the pollen will not be deposited upon the 

 stigma of that flower. Suppose it were now to visit another flower, 

 guided as before to the centre, it would leave some of the pollen 

 upon the viscid stigma, because, in inserting its proboscis into the 

 spur of the corolla it would brush the proper viscid surface of the 

 stigma, there being no valve to hinder it in its entrance, as there 

 is upon its exit from the flower. 



In Kalmia, sp. (Fig. 15 and 17), the corolla is large, and has a 

 number of pouches, into which the stamens are inserted by their 

 anthers. As the flower opens, the filaments of the stamens are put 

 in great tension, and whenever an insect lands upon the flower, 

 the corolla is violently depressed. The stamens are at the same 

 time dislodged from their pouches, springing forward with great 

 force, scattering their pollen upon the insect as well as on the 

 neighbouring flowers. 



In Parietaria officinalis, or Wall Pellitory (Fig. 14), we have 

 protogynous dichogamy. Before the flower opens, the little red 

 stigmas appear at the mouth of the flower (Fig. 14), and are ready 

 to receive any pollen that may be brought into contact with them. 

 In the male stage the stigmas drop off. The anthers are lodged in 

 little pouches at the base of the ovary, and the filaments are very 



