^joumS, aKmS] Primordial Ty]pe of Animal Life. 233 
The expression that " the digestive apparatus is reduced to its 
simplest possible condition " clearly points to the least and not the 
most highly differentiated family ; in other words, to the Forami- 
nifera. On the other hand, the idea of their " moving actively in 
search of food," " introducing food into the interior of their hodies," 
and the possession of " a special contractile organ," as clearly point 
to the Amoehans ; for I presume no one will undertake to say these 
epithets are applicahle to the Foraminifera. Again, had this sup- 
plementary description been intended to apply principally to the 
Foraminifera, it is singular that all allusion to the remarkable 
symmetry and complexity manifest in their shell formation should 
have been omitted in it. But vnthout going further, I hope the 
correctness of the assertion with which I opened these remarks will 
already have become manifest, namely, that it is high time that the 
student who desires to investigate the characters of this most in- 
teresting section of the animal kingdom should be enabled to turn 
with confidence to some accredited type of primordial life and take 
it as his starting-point, instead of finding himself involved in a 
maze which must effectually bafSe him. 
I now beg leave to say a few words regarding the so-called 
"Cyclosis," or circulation of minute granules, which it has been 
customary to assert takes place both within the body of the Forami- 
nifera and along the projected pseudopodia. Although well aware 
that my views on this as on other vital phenomena observable in 
the protoplasm of the Ehizopoda are not in accordance with those 
which have been so authoritatively enunciated by others, I feel 
bound to express my conviction that such cyclosis is in no way 
to be regarded as an independently acting vital function resident 
either in the protoplasm proper, or in the granules suspended within 
it ; but is a purely mechanical result, affecting the granules only 
through movements executed by the vital contractility which is an 
inherent attribute of animal protoplasm. "When these movements 
cease, the circulation of granules ceases : when they are resumed, 
the circulation of granules is resumed also. In the testaceous 
families of the lower types, and notably in the Foraminifera and 
Polycystina, these movements become manifest only to the extent 
of causing a nearly constant efffux and influx, in opposite directions, 
of the protoplasmic matter entering into the formation of the pseudo- 
podia and also in that portion of it which, in most cases, consti- 
tutes a delicate investing layer on the exterior surface of the shells. 
It is, however, in the naked Amoehse that the pseudo-cjclosis attains 
its most energetic and characteristic limit, and we can most readily 
perceive that it is produced by a mechanical and not a special vital 
agency. In the large pseudopodia of Amoeba we see at once that 
the appearance of an advancing and a retrograde current is due to 
the fact that the lower surface of the organism is fixed as it were 
