I 8 PLANT LIFE. 



summer. Later, Brambles and perhaps a second 

 bloom of Dog's Mercury continue the succession until 

 with the first winter-cold almost everything vanishes. 

 This intermingling of the floral seasons is very distinct 

 in the case of woodland flowers, but it is also easily 

 noticed in cultivated fields, where some weeds flower 

 before the corn or turnips; others, such as the Thistles, 

 flower exactly at the same time, so that their seeds 

 may be sown with the corn ; and others, again, spring 

 up and flower in the stubble, or after the turnips have 

 been removed. 



Even during the course of one day, the flower- 

 surfaces ready for an insect's proboscis do not remain 

 the same. Linnaeus drew up a Shepherd's clock to 

 illustrate this point, and it has been very well worked 

 out by Kerner and others. Roses open very early in 

 the morning, about 4 or 5 a.m. ; Epilobium about 6 or 

 7 a.m. ; Convolvulus at 7 or 8 a.m. ; Gentians, Veronicas, 

 etc., between 8 and 9; Tulips between 9 and 10. 

 The Centaury does not awake until between 10 and 



I I a.m. Then John-go-to-bed-at-noon shuts its flowers, 

 perhaps not quite at midday, but very early in the 

 afternoon. The Honeysuckle opens and sends out its 

 sweet scent at 6 p.m. ; and from 8 p.m. to 3 a.m. such 

 evening flowers as Silene noctiflora are ready for the 

 Owlet-moths. 



The net result of this daily and monthly variation, 

 ensures a series of waiting flowers for the satisfaction of 

 any wandering insect. 



The close connection of the flower and insect world 

 comes out very clearly also from geological data. Cock- 

 roaches existed in the Silurian period. The warm and 

 moist forests of Fern and Club-moss in the Carboniferous 

 epoch were not without insect life, for Mayflies and 



