248 Dr, Jomisoi;*s further observations 
I was at length fortunate in obtaining it through the libera- 
lity of its very ingenious author, who obligingly presented 
me with his only remaining copy. 
This Gentleman, after noticing the considerable reproduc- 
tive powers of the planarice in general, but more particularly 
conspicuous in that species he terms the P. felina, and which 
from his description I conjecture to be the P, comuta, ob- 
serves, that having occasionally seen some of these creatures 
deviate from their natural figure in having two tails, &c. (an 
event however of so rare an occurrence, that I have in no 
instance met with such in the many thousands submitted to 
my inspection) it occurred to him that monstrosities of this 
kind might be obtained by artificial means, founding the 
practicabily of this measure on what had passed under his 
reviews. One of these monstrosities he thus describes, ‘‘ the 
planaria in relation to others was of small size, its tail was 
bifid, and out of the cleft gre\v a body, separated and distinct 
from the main trunk of the animal, which by some strange 
and anomalous proceeding had been surmounted by a head, 
lively and well defined. In subjecting this planaria to the 
microscope, numerous black specks, the supposed eyes, ap- 
peared surrounding the larger head, and they environed the 
margin of the smaller head also. In the course of a week or 
little more the posterior head had separated by spontaneous 
division, and had disappeared. But soon afterwards a kind 
of projection occupied its place ; and it was not without amaze- 
ment that I beheld this projection vegetate into a new head, 
resembling the one which had been lost. About a month 
having elapsed, it was well shaped and entire. My belief 
being thus corroborated in the probable effect of experiment, 
