Abraham Trembley
A young tutor at the time, the Swiss Abraham Trembley (1710-1784) wrote in November 25, 1740:
"The first operation I performed on the polyps was to cut them transversely.... I place it with a little water in the hollow of my left hand....When I have it as I want it, I delicately pass one blade of the scissors, which I hold in my right hand, under the part of the polyp's body where it is to be severed. Then I close the scissors." (translated by Lenhoff and Lenhoff)
Such amputations resulted in two fragments that were each capable of regenerating an entire polyp on their own. Thus began the experimental study of regeneration in the metazoans. Because of their morphology, and their ability to regenerate, the polyps reminded Trembley of the mythical Hydra, and adopted this Greek name to refer to them. This name endures to this day and so does the study of regeneration in Hydra (cnidarians).
An English translation of Trembley's work can be found in Sylvia and Howard Lenhoff's "Hydra and the Birth of Experimental Biology-1744." This book can be ordered through Amazon.com.An index of this translation has been recently released by Sylvia and Howard Lenhoff.

Below is a 19th century illustration of various hydra taken from The Wandtafeln of Rudolph Leuckart (1822-1898)