282 Mechanical Reception of Nutriment into the [May, 
In 1875, during an anatomical examination of the cave 
newt ( Spelerpes fuscus ) he observed in the intestinal canal 
large extents of ordinary epithelia, which in recent prepara- 
tions displayed no basal margin. These free borders 
appeared to him devoid of sharp limits, irregularly ragged, 
and resolved into fibres. The protoplasm on the free 
margin of certain cells was engaged in an active amoeboid 
motion. He distinctly observed slow changes of form in 
the cell-processes, and twice he saw those processes retracted 
into the body of the cell. 
Dr. Wiedersheim further succeeded, when examining 
living sharks, in confirming an observation of Edinger. 
The latter found in the mucous membrane of the intestine 
of fishes a large mass of lymph cells, which even penetrate 
between the experiments. He further succeeded in proving, 
by means of experiments with chopped meat, mixed with 
graphite, that these lymph corpuscles took a distinct black 
colour. He even believes that he could here and there 
recognise the black pigment in the interior of single 
epithelial cells. Hence he considers himself justified in 
concluding that the intestinal epithelia of fishes, like 
those of Spelerpes fuscus , are capable of amoeboid move- 
ments. 
Although Dr. Wiedersheim has not succeeded in diredtly 
feeding the epithelial cells of fishes with granules of 
pigments, he is still of opinion that both the lymph cells of 
fishes and the epithelial cells of newts subserve a me- 
chanical absorption of nutriment. The adlive amoeboid 
movements of the intestinal epithelia have been fully 
established in vertebrate animals, as well as in many 
evertebrates. This amoeboid motility of the cells he regards 
as a primeval heir-loom from the lowest vertebrates. He 
does not, however, deny that with the decrease of the 
individual activity of the single cells their universal me- 
chanical power of taking up the most varied kinds of 
nutriment declines in vertebrate animals, and this the more 
as the chemistry of digestion begins to play a more im- 
portant part in consequence of the development of different 
kinds of glandular apparatus. In other words, we have 
seen that the original method of taking up nourishment 
was purely mechanical, depending on the adtive intervention 
of the cell itself. This naturally does not exclude a true 
intercellular chemical assimilation. 
In the higher vertebrates — i.e. } from the osseous fishes, 
and perhaps even from certain Selachii upwards — the 
