v.] 



THE DEAD NETTLE 



145 



absent or rudimentary, while the other four lie along 

 the outer arch of the flower, on each side of the pistil. 

 They are not of equal length, but one pair is shorter 

 than the other ; the inner pair in some species, the 

 outer pair in others being the longest. Now, why 

 is this } Probably, as Dr. Ogle has suggested, be- 

 cause if the anthers had lain side by side, the pollen 

 would have adhered to parts of the bee's head which 

 do not come in contact with the stigma, and would 

 therefore have been wasted ; perhaps also partly, as 



-Flower of Lamium album. 



Fig. III. — Section of ditto. 



he suggests, because it would have been deposited 

 on the eyes of the bees, and might have so greatly 

 inconvenienced them as to deter them from visiting 

 the flower. Dr. Ogle's opinion is strengthened by 

 the fact that there are some species, as for instance 

 the Foxglove, in which, as shown in Figs. 100 — 102, 

 the anthers are transverse when immature, but become 

 longitudinal as they ripen. 



But to return to the Dead Nettle. From the 

 position of the stigma which hangs down below the 

 anthers (Fig. 11 1 sf), the bee comes in contact with 



L 



