151 
Among living types, the Siluroids are probably most 
nearly akin to Dinichthys. This group includes our cat-fishes, 
which have, instead of bony armor, only a hard, tough skin, 
and certain East Indian species, which possess, to some extent, 
a plated covering. 
This paper was illustrated by drawings of natural size, and 
by a series of photographs of the remains of the new speci- 
men found by Mr. Terrell. 
Pror. Louis EissereG read a paper entitled, Notes on 
Physical Regeneration—a Contribution to the Doctrine of 
Evolution. 
This paper discoursed of what may be termed Hereditary 
Molecules, and was designed to show the modifications 
which, according to the author, must be made in the doc- 
ne of evolution. 
To simplify the subject as much as possible, the genealogy 
of a child was traced. The impregnated ovum from which 
it grows consists of matter derived from the bodies of its 
parents; and it is assumed that some of the particles of this 
matter are retained in the child’s body until, later in life, they 
are contributed to the formation of a new being, so that the 
germ of the new being contains some of the very particles of 
matter originally derived from its grandparents. The objec- 
tions that might be urged to this assumption were then con- 
sidered and disposed of. It was said that the transmission of 
the identical material particles to the grandchild, is a point 
not absolutely essential to the argument, since the transmis- 
sion by the parents of particles rendered like those derived 
from the grandparents, would meet the case; nevertheless 
actual material transmission of grand-parental molecules was, 
for reasons given, regarded as most probable. The transmit- 
ted molecules were called plastidules, meaning plastid-mole- 
cules,—plastids being the term applied to the ultimate forma- 
tive elements of organic bodies. To those who can more 
readily conceive the idea of force being transmitted from 
generation to generation, than matter, it may make the sub- 
ject clearer to state that a plastidule is looked upon by the 
author quite as much as a center or bundle of force as of 
matter. With the assumption of hereditary molecules, the 
fact of resemblances in features of children to their grand- 
parents, and of other inheritances, predisposition to diseases, 
reversion, etc, are quite naturally explained. 
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