II RANUNCULACEiE 63 



through this space, as shown in Fig. 36, a, /S, a' , so that 

 the proboscis of the bee, in passing down to the honey, 

 can hardly fail to come in contact with them. After 

 shedding their pollen, they turn down again, and when 

 each anther has thus raised itself and again retired, the 

 pistil in its turn takes possession of the place, as shown 

 in Fig. 36, 7, S, st, and is thus so placed that a bee 

 which has visited a younger flower and there dusted its 

 proboscis can hardly fail to deposit some of the pollen 

 on the stigma. Fig. 36, a, represents a young flower 

 seen from the front after the removal of the calyx ; it 

 shows the entrance leading to the nectary, in which are 

 seen the heads of two mature stamens, a' , while the 

 others, a, are situated in a cluster below. Fig. 36, /8, 

 represents a section of the same flower. Fig. 36, 7, 

 represents a somewhat older flower in the same position 

 as Fig. 36, a. In this case the stamens have all shed 

 their pollen and retired, while the stigmas st, on the con- 

 trary, have risen up, and are seen projecting into the 

 space m. Fig. 36, S, represents a side view in section of 

 this flower. Anthophora pilipes and Bomhus liortorum 

 are the only two North European insects which have a 

 proboscis long enough to reach to the end of the spur of 

 Delphinium elatum. A. pilipes is, however, a spring 

 insect, and has already disappeared before the Delphinium 

 comes into flower, which in the neighbourhood of Lipp- 

 statt appears to depend for its fertilisation entirely on 

 Bomhus hortorum,, though Boissier assures us that in 

 France and in the Alps it is visited by several other 

 species. 



The leaves are cut up into linear segments. T have 

 already suggested [ante, p. 24) one probable reason for 

 this. Another advantage of leaves being cut up is that 

 they let light through to those below. Of course there 

 must be some shadow ; but as the sun moves across the 

 sky, one part of the lower leaves after another is lit 

 up, and this is sufficient for them. Species like the 

 Mulleins, with entire leaves, form a conical pyramid, 

 the lower leaves thus being well lighted ; while those 



