Dr. Mantell’s Lecture on Zoophytes. 331 
ground, the skin becomes distended, and the graceful form of life 
disappears, chemical changes begin to operate, decomposition takes 
place, and finally dust returns to dust and the spirit of man to Him 
who gave it. Dr. M. next described the essential characters of ani- 
mal existence and contrasted it with that of the vegetable kingdom; 
defining the former as possessing certain determinate external forms, 
which were gradually developed, and having an internal organiza- 
tion possessing systems of vessels for effecting nutrition and support, 
combined with a nervous. system communicating sensation and vol- 
untary motion. ‘The external forms are as various as the imagina- 
tion can conceive, from the god-like image of man to the shapeless 
mass of living jelly that floats on the waves; from the elephant and 
whale to the insect and monad, of which five hundred millions are 
contained ina single drop of water: in short, so various and dissimi- 
lar are the forms of animals even on our own globe, that the opinion 
of astronomers that the inhabitants of the glorious orbs around us 
must of necessity, from the different description and conditions of 
the respective planets, be totally unlike any that exist on the earth, 
can no longer appear marvellous and incredible. ‘The lecturer then 
observed, that of all the extraordinary forms, none were more unlike 
what the common observer would conceive of animals, than the 
sponges, corals, &c., which were known by the name of zoophytes, 
from two Greek words signifying animal plants. In this very town 
Mr. Ellis, in 1752, first discovered the animal nature of sponges, and 
many other forms previously supposed to be plants. Dr. Mantell 
then described the flustra which occurs on the rocks, and on almost 
every leaf of sea weed, appearing like a fine lace work. When 
viewed through a powerful microscope, every pore in this lace work 
is found to be the cell of a polypus or living animal, in form of a 
tube with the border fringed with bony feelers or tentacula. These 
were the instruments by which the animal obtained its prey, it might 
be seen expanding these feelers, then suddenly contracting them, 
and retreating into the cell, and then again protruding forth, the 
whole surface of the flustra exhibiting at every pore a living form. 
Dr. M. then pointed out on his beautiful drawings magnified views 
of these extraordinary beings, drawn from living specimens from the 
sea shore. The jflustra (which the lecturer observed he took as the 
type of zoophytal animation, because it was so common,) is a com- 
pound animal, consisting of a fleshy substance with an internal cal- 
careous skeleton, the foci of vitality consisting of polypi, by whose 
