from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A portion of the proboscis that is adapted as a sucking organ in many insects.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A sucking organ, in the form of a proboscis, in many insects and crustaceans
from the GNU version of the Collaborative International Dictionary of English
- n. The sucking proboscis of various insects. See lepidoptera, and diptera.
from The Century Dictionary and Cyclopedia
- n. The sucking-organ of an insect or a crustacean; a suctorial proboscis.
Antlia: the spiral tongue or haustellum of Lepidoptera.
We will suppose that a change takes place in a particular orchid, that the nectary recedes to a greater distance from the point to which the insect can penetrate, and so an advantage is given to those insects in which the haustellum is of a length above the average.
The insect derives an advantage from its increased haustellum, but what advantage does the plant derive from its retiring nectary?