B AW DEN, Movements of the Neurone. 249 



changes of form nnd position. This has been shown by the further 

 researches on this crustacean by Samassa (95 and 96) and by Carlton 

 {23). The same may be said regarding the inchisions observed by 

 Svierczewski (105) and Freud (37). Tanzi's arguments (106) for the 

 gradual approximation of the nerve branches by growth of the den- 

 dritic processes are doubtless in a general way correct, but they have 

 no direct bearing on the question of such amoeboid movements as 

 would be necessary to account for the relatively abrupt phenomena of 

 sleep and awakening, association of ideas, memory, etc. The same 

 remarks might be made with reference to the researches of Jacques (49) 

 as cited by Deyber. 



We pass to the proofs from analogy. The first of these proofs is 

 found in general well-known cellular changes which take place under 

 certain conditions in epithelial, glandular, and in cicatricial tissues. 

 These tissues have all been studied with more or less care and with 

 varying results for the purpose of demonstrating microscopical changes 

 connected with their functional activity. Deyber includes under the 

 term "amoeboid movement" all kinds of protoplasmic movements from 

 those which botanists describe in the circulation of the protoplasm of 

 plant cells to the oscillatory movements of the cilia of animal cells. To 

 bring under the same name movements of such diverse nature seems a 

 little forced, to say the least. But the study of the Protozoa has shown 

 the existence, he says, of all gradations between what is ordinarily 

 called amoeboid movement to the true vibratile ciliated cell. The 

 researches of Schiefferdecker and Kossel (98) are cited. The presence 

 of the amoeboid property is claimed also for the so-called myo-epithel- 

 ial cells surrounding the sudoriparous tubes which are found in the ex- 

 ternal layer of the skin. Gland cells, says Deyber, exhibit movements 

 during the process of secretion. The researches of Ranvier (86) on 

 the saUvary glands of the frog are cited. Reference is made to Ran- 

 vier (89) also for the changes which take place in the cells involved in 

 the healing of a wound which, it is claimed, exhibit amoeboid 

 movements. 



In criticism it is to be said that in the cases of the epithelium and 

 gland cells we are dealing with changes in the interior of the cell unac- 

 companied by alteration in the external form. In the case of the cili- 

 ated epithelial cells there is, properly speaking, no amoeboid property 

 such as we find in the amoeba or leucocyte, but only a certain vibra- 

 tion of the fixed cilium. The changes cited m glandular tissue are 

 obviously open to other modes of interpretation besides that of amoe- 

 boid movement. The reference to the myo-epithelial cells of the sud- 



