TSlossoni Hosts j/ui Insect Guests 



distinctly separated from the pollen. The " lip " is 

 extended forward as a hospitable threshold to the 

 insect. And to what insect might we assume this 

 invitation of color, fragrance, nectar, and threshold 

 to be extended ? 



Let us consider the flower simply as a device to 

 insure its own cross-fertilization. The insect 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 blossom 

 wdiich it visits, and leave it upon its stigma. 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 Are- 

 thusa, 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 brinorinor their bodies in contact 



o o 



with the stigma. Smaller insects might creep into 

 the nectary and sip without the intended fulfil- 

 ment. It is clear that to neither of such vis- 

 itors is the welcome extended. What, then, are 

 the conditions embodied ? The insect must have a 

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



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