In regard to the relation of the cortex to _motility_, SWEDENBORG expresses himself much more definitely. This activity of the brain SWEDENBORG also regarded as derived from the small cortical elements, the ›_Sphaerulae_› or ›_Cerebellula_›.[37] He ascribes to them, on the one hand, a high degree of _self-determination_, so that they could perform their functions independently of each other, this on the basis of certain anatomical conditions, such as their position in respect to each other in separate cavities, and their connection each with its own special nerve-fibre, and, besides, also on the basis of certain clinical and pathological observations;[38] but on account of other anatomical conditions, such as the aggregation of the ›Cerebellula› into larger and smaller groups, as into gyres, and groups of gyres, etc., as well as on certain other grounds, he ascribed to them also the ability to _cooperate with each other_ when necessary.[39] In consequence of this the brain possesses, as he says, the power and choice of influencing whatever nerves and muscles it will, and of stimulating them to activity. (›Proinde Cerebri secundum ordinatam ejus substantiae dispositionem in potentia et arbitrio est, quascunque velit fibras, aut fibrarum fasciculos, et consequenter nervos et musculos inspirare et ad agendum excitare.› Œc. R. A. II., 153). It was impossible for him to express himself as to what parts of the cerebrum or which convolutions, _gyri, correspond to the respective muscles_, but _he refers to experimental investigations of animals_, by which this might be discovered.[40] But although the brain would then be able to govern every muscular action, it was not employed every time such an action was to be performed. No, in the medulla oblongata and in the grey substance of the spinal cord there were _subordinate, secondary motor centres_, and these governed the automatic and habitual movements, so that, for the performance of these, the brain need not be disturbed in its higher functions. Only for the purely voluntary motions were impulses from the cerebrum necessary.[41] SWEDENBORG has thus clearly located _the ›causa principalis› of the voluntary movements_ in the _cortex of the cerebrum_, or more definitely, in _the cortical elements and in groups of such elements_, although in this work ›Œconomia Regni Animalis› he did not succeed in more closely defining the position of the various motor centres. From all that I have here brought forward concerning the functions which SWEDENBORG ascribes to the cortical substance of the brain, it is evident that he succeeded in coming to the full conviction that it is _through the activity of the ›Cerebellula›_ (or as we express it, through the cerebral nerve-cells) that _the perception of sense-impressions and the impulses to voluntary motions arise_.