254 Journal of Comparative Neurology 



to the morphine for some time, he killed by destruction of the medulla. 

 Another dog he trepanned on both sides at the level of the crucial sul- 

 cus and allowed it to recover from the shock ; the next day he took a 

 small portion from the left hemisphere and then, after morphinization, 

 he took a similar portion from the right hemisphere. All these pieces 

 he treated in the same way. He found the cellular modifications iden- 

 tical in all these cases. Whereas in the normal animal before morphin- 

 ization the terminal dendrites were covered with gemmules regularly 

 distributed, in the operated animals these dendrites lost their gemmules. 

 That is, according to Deyber's interpretation, these gemmules were 

 retracted into the body of the terminal branches which bore them. But 

 the retraction in the case of the operated animals was not confined to 

 the gemmules, since the dendrites themselves took on a moniliform ap- 

 pearance. Such monihform dendrites always ended in a terminal 

 granule which was relatively large. If the morphinization was not so 

 profound, the same results were discoverable, but were to be observed 

 only in the finer ramifications of the dendrites. In another series of 

 experiments Demoor trepanned the two sides of the head of a dog 

 asleep with morphine. He then gave it liberty for thirty-six hours. At 

 the end of that time he removed a piece from the left hemisphere and 

 to the other side applied a strong electric current, immediately after 

 which he excised a piece from that (the right) side. These pieces he 

 treated in the same manner. The cells of the first piece were normal, 

 that is, presented the gemmulated appearance and were not moniliform. 

 In other words, the influence of the morphine was temporary only, 

 producing a modification which disappeared during the thirty-six hours 

 of repose. In the other piece, which had been subjected to the electric 

 current, the cells were globular and very irregular in appearance as 

 well as having their dendrites moniliform and granulated. In a subse- 

 quent paper Demoor (27) relates his observations to the theory of sleep, 

 in somewhat the same way as Duval. Demoor (28) summarizes what 

 he considers to be the significance of the moniliform state of the neu- 

 rones for the theory of amoeboid movement as follows : (a) This monil- 

 iform state is indicative of a retraction of the protoplasm of the den- 

 drites, (b) This retraction breaks the contact between the cellifugal and 

 cellipetal ramifications of the neurones, (c) The nerve elements or neu- 

 rones are plastic, and this property is of great significance from the 

 point of view of their functioning and interconnections. A recent re- 

 search by Hodge, undertaken with Goddard,i supports Demoor's con- 



1 This research is briefly reported in Science, N. S., Vol. IX, No. 217, 

 p. 288. 



