Ong. 
PLANARIA. 09 
eon 
propagating by ova, as I presume is the case, some short intervals have been 
accidentally omitted. Many of the largest survive readily during several 
months. 
These creatures feed alike on animal and vegetable matter, particu- 
larly, as I think, on decaying leaves, when the intestines seem to be 
coloured very dark. But the animal, on the intestines being emptied of 
their contents, always becomes pure white. 
The Planaria lactea lives in society. Both in the natural and artifi- 
cial state, it lurks among decaying leaves. I have seen between eighty 
and ninety huddled together on the under surface of a large decaying 
beech leaf. 
Tt is an animal of nocturnal habits. Let a large collection of miscel- 
lancous matter be made from the places where it dwells, and emptied 
into a capacious vessel holding a gallon and a half, by adding such a 
quantity of fresh-water that a fourth or fifth part of the vessel above re- 
mains clear and free, the Planariz: beginning to move in the evening, 
and gradually ascending the sides, may be observed in multitudes floating 
supine on the surface. But many willbe found to have descended in the 
morning. 
Pirate XVI. 
Fic. 5. Planaria lactea, abstinent. 
6. Another specimen having fed, back. 
7. Belly. 
8. Head, enlarged. 
9. Ovum. 
Prats XV. 
Fic. 4. Planaria lactea having fed, and the interanea full, enlarged, to shew 
the distribution of the vessels. 
5. The same, anterior portion, shewing the eyes and the formation of 
vessels, more enlarged. 
6. Posterior portion on the same scale. It will be observed that here 
the middle part is omitted, and only both the extremities repre- 
sented. 
