A FEW NATIVE ORCHIDS 1 87 



is welcomed; it must alight and sip the nectar; 

 in departing it must bear away this pollen upon 

 its body, and convey it to the next Arethusa blos- 

 som which it visits, and leave it upon its stigma. 

 These are the conditions expressed ; and how 

 admirably they are fulfilled we may observe when 

 we examine flower after flower of a group, and 

 find their nectaries drained, their anther cells 

 empty, and pollen upon all their stigmas. The 

 nectar is here secreted in a well — not very deep — 

 and the depth of this nectar from the entrance is 

 of great significance among all the flowers, having 

 distinct reference to the length of the tongue 

 which is expected to sip it. In the Arethusa, it 

 is true, the butterfly or moth might sip at the 

 throat of the flower, but the long tongues of these 

 insects might permit the nectary to be drained 

 without bringing their bodies in contact with the 

 stigma. Smaller insects might creep into the 

 nectary and sip without the intended fulfilment. 

 It is. clear that to neither of such visitors is the 

 welcome extended. What, then, are the condi- 

 tions embodied ? The insect must have a tongue 

 of such a length that, when in the act of sipping, 

 its head must pass beyond the anther well into 

 the opening of the flower. Its body must be 

 sufficiently large to come in contact with the an- 



