330 THE AMERICAN NATURALIST. [Vor. XXXVI. 
differentiated in three dimensions could divide itself by material 
means into the elements of an equipotential system.” “If each 
organism produced but one egg, then the materialistic conception of 
heredity might be true, in which case there need not be of course a 
regulative restitution; but since the organism produces many eggs, 
the conception is impossible ; because, (1), in order that the develop- 
mental phenomena may be deduced materialistically they must be 
thought of under the assumption of a complicated primary machine, 
but, (II), on account of the required division of the complex potencies 
into the elements this assumption cannot be made." 
Perhaps these statements may be clearer in the following quotation, 
in which both the first and the second proofs of the autonomy of the 
life process are considered together. “The preceding phenomena 
can be interpreted only on the basis of machines of a complicated 
sort — but such machines can, for other reasons, not exist. They 
cannot exist, in the first place, because a machine does not remain 
the same when we take away any of its parts, or when we rearrange 
its parts; for machines do not possess the property of division." It 
can scarcely be claimed by the author that the discovery that organ- 
isms are not machines is new, but having admitted this, it does not 
seem to follow that, therefore, there must be a vitalistic principle in 
nature. There seems to us to be a great hiatus in Driesch's argu- 
ment, and in any case his conclusions appear to be based rather on 
our ignorance of what the organism really is than on a demonstration 
that it is something that cannot be conceived under a causal-mechani- 
cal point of view. ji 
III. In the final section of the paper a number of philosophical 
and metaphysical topics are discussed, and the author defines his 
position in regard to the use and meaning of the terms “ mechanism ” 
and “ causality.” bi ae i 

ZOOLOGY. 
Fauna of Switzerland. — The origin of the present fauna of 
Switzerland from that of the glacial period has been the subject of 
repeated investigations, but these studies were mainly restricted to 
the higher forms of terrestrial life. A recent publication by Prof. 
F. Zschokke' not only gives a condensed review of our knowledge 
- lZschokke, F. Die Tierwelt der Schweiz im ihren Beziehungen zur Eiszeit. 
Basel, 19or. 
