BEES AS FERTILISERS. 303 



which careful inspection will show to be formed by 

 the upper ends of a number of tubular flowers. 

 Making a cross section, we find the central flowers, 

 or florets, less developed than those at the side ; 

 so that, by passing from the centre to the cir- 

 cumference, we trace the steps of progress through 

 which each floret must pass. In No. 1, Fig. 63, the 

 extension of the corolla tube at its lower end, to ac- 

 commodate the ovary, is seen, while above, the corolla 

 is just opening. About a day later this floret will 

 have assumed the form of No. 2, where the anthers 

 have grown up partly into view. In this order the 

 anthers and their filaments surround the style, the 

 anthers uniting at their edges, so as to form a tubular 

 sheath, into which the pollen is shed. The style fills 

 the tubular sheath in its lower part, like the rod of a 

 popgun, and, as it grows, drives the pollen before it, 

 until at last the anther tube gives way, and the 

 pollen is pushed out as we see it at Nos. 4, 4', Figs. 

 63 and 64, when insects, searching for sweets, and 

 collecting or eating the pollen, will get dusted 

 beneath. The style still grows on, and now appears 

 (5) having its end covered with filamentous hairs, 

 which have acted the part of a chimney sweeper's 

 machine in driving the pollen before it. A day or 

 two later, when its fertilising dust has all gone, the 

 style splits, and curves back (6), so as to expose 

 the now receptive stigmatic faces ; and thus, as in so 

 many similar cases, crossing is secured. Coming 

 now to the outside floret, carrying one of the rays 

 which make the external ring of the flower-head, we 

 find a distinct alteration. Here the style carries no 



