TRANSACTIONS OF SECTION TI. 645 
dissociation. The startling limitations of the parasitic life, its uneconomic 
nature, its astounding liability to infection, to padogenesis, and reproductive 
nemesis mark it as a life of failure. 
One inference is that the retention of vital intra- and extra-organismal cor- 
relations depends upon maintenance of economic integrity least calculated to 
distort the intra- and extra-organismal metabolic balance. 
FRIDAY, SEPTEMBER 6. 
The following Papers were read :— 
1. The Physiological Basis of Memory and Abstraction. 
By Max VERWwoRN. 
Upon the basis of the neurone theory the problem which arises for physio- 
logical psychology is the ascertainment of the physiological conditions of the 
sensory processes in the neurones. Here one of the first problems is the question 
concerning the fundamental principle involved in memory: what are the traces 
remaining after excitation, produced by the sensory processes in the neurones, 
concerned? It has been assumed that they consist in molecular alterations result- 
ing from the process of excitation. The maintenance of that view meets, how- 
ever, with some difficulties. The molecular alterations brought about in the 
neurones by the stimulus during excitation consist, as has previously been shown, 
in a disturbance of the metabolic equilibrium by an increase of the processes of 
oxydative disintegration. Immediately following each excitation, however, 
metabolic equilibrium is again restored, and every trace of the excitation process 
appears obliterated. Still, even though the process produces no molecular altera- 
tion, a secondary result remains, which consists in an increase of the mass of the 
living cell. This only becomes clearly manifest when the excitation is of frequent 
recurrence, and is then expressed by functional hypertrophy. ‘The presence of 
the latter can be demonstrated in the neurones as well as in every other living 
substance. It forms the cellular basis of memory by increasing the intensity of 
the discharge of impulses, and with this the specific action of the neurone. 
This recurring use leads to a facilitation of the tracts (Ausschleifen der Bahnen), 
and thus to a greater intensity of the specific action of neurone chains resulting 
from the repeated demands. We find this demonstrated in the association pro. 
cesses of the cerebral cortex by the predominance of the facilitated conceptions, 
in response to a stimulus over others not practised in this manner. In lapse of 
memory resulting from want of practice, the reverse process takes place. Here 
the unused neurones fall into an atrophy by inactivity. 
These facts afford us insight into the process of abstraction. All our concep- 
tions are complex in their nature. The abstract conceptions are distinguished 
from the concrete by the fact that the former, in the specific manner of the adjust- 
ment of their components, have no correlation in the sensory world, whereas the 
latter are fully in accordance with those things which can be perceived through 
the senses. In spite of this, however, the material from which the abstract con- 
ceptions are built up is likewise individually derived from sensory perception, 
and even the most abstract conceptions are composed of sensory elements. In 
the genesis of abstract conceptions the principle is merely that in a number of 
association complexes gained by sensory perception, having in part common, in 
part different components, the common components which return with greater 
frequency are developed by use, whereas the special components, which recur 
seldom, or not at all, fall into atrophy and recede into the background. As the 
neurone stations, which correspond to the common components, undergo, by more 
frequent functional demands, a hypertrophy, they consequently predominate later 
in response to a stimulus by the intensity of their discharge, that is, of their 
specific function. Thus, finally a framework of associated conceptions is formed, 
in which only the most frequently recurring components of a complex are left 
over, whilst the other, through atrophy by inactivity, have disappeared more and 
