94 'Journal of Comparative Neurology and Psychology. 



heart and the smooth muscles of the vertebrates as well as to the muscles in molluscs 

 show that in these muscle systems the nerves end not in free fibrils but in end nets. 

 Each nerve can form a closed net for itself or there may be a continuous net formed 

 by an anastomosis between the various nerve filaments. These nets are limited to 

 the final branches of the nerves and are, according to Hofmann, entirely inde- 

 pendent of the presence of ganglion cells. The appearance of the nerve nets with 

 nuclei is an artifact. Physiologically the innervation of the smooth muscles in 

 vertebrates and molluscs, in so far as there are no ganglion cells present, is a local- 

 ized one, and there is no general radiation of the excitation aroused in the central 

 nervous system. Certain conclusions that would follow from this view of the 

 matter were referred to by the speaker, and the paper was discussed by Bethe and 

 Langley. 



In spinal animals, Professor Sherrington (Liverpool), H, demonstrated the 

 effect of "removal of stimulus from the stepping reflex of the spinal dog "and the 

 "influence of strychnine on the reflex inhibition of skeletal muscles." A cat was 

 shown in which all the nerves of the four feet were severed, but the animal was able 

 to walk well and accurately. In this animal burning the feet did not produce a 

 reflex withdrawal and there could have been no nerve conduction to the spinal cord. 

 This suggested that an important source of stimuli for the reflexes of walking or 

 stepping is in the proximal part of the limbs. To confirm this supposition Sher- 

 rington divided the spinal cord in a dog at the tenth thoracic vertebra (the animal 

 shown at the congress had the operation performed almost three years ago), and 

 when the limbs of the dog were held from the ground they executed the stepping 

 reflex. When one thigh was gently lifted the reflex immediately ceased in both 

 legs. On allowing the thigh to hang again the reflex began immediately with the 

 same activity as before. The reflex stepping was inhibited by pinching the tail, 

 but on releasing the tail it began with ncreased activity, quicker and with greater 

 amplitude. The antagonistic action of strychnine on the reflex inhibition of 

 skeletal muscles was shown by Sherrington in the following manner: In a decere- 

 brized or spinal cat the vasto-crureus muscle was prepared for examination. All 

 the other muscles of the leg were paralyzed by severing their nerves or their attach- 

 ments. After this was done it was found that stimulation of the internal saphenous 

 nerve below the knee always caused reflex relaxation of the vasto-crureus, which in 

 normal action produces an extension of the leg. After the inhibition was obtained 

 strychnine was injected and then stimulation of the internal saphenous nerve was 

 followed by reflex contraction of the vasto-crureus. In some way the strychnine 

 acted on the spinal cells to change the central inhibition into excitation. 



Dr. M. Phillipson (Brussels), H, demonstrated the movements of a spinal dog 

 and considered the subject, "Sur les reflexes croises chez le chien." The dog had 

 been shown to the congress in 1904 after a complete section of the spinal cord in the 

 dorsal region, and at that time it showed the following: Numerous direct and 

 crossed reflexes, principally of direct extension, direct flexion, and crossed exten- 

 sion; when the animal was suspended vertically the feet of the animal were moved 

 rhythmically; when hung horizontally the feet moved faster and the movements were 

 seen to be those of walking, trotting, and galloping; when placed on the ground the 

 feet moved to bring about the propulsion of the animal, and the feet movements 

 were correct in point of view of coordination but strongly ataxic. In the same 

 animal the dorsal columns of the cord in the lumbar region were extirpated to deter- 



