150 GERMINATION 



foundations and have not been found to stand experimental 

 tests. 



" Then there are what we may term histological theories 

 of sleep, and these are equally unsatisfactory. The introduc- 

 tion of the Golgi method opened a fresh field for investigators, 

 and several have sought to find by this method a condition 

 of the neurons produced by narcotics, such as opium and 

 chloroform, which is different from that which obtains in 

 the waking hours. 



" Demoor and others found in animals in which deep 

 anaesthesia has occurred, that the dendrites exhibit monili- 

 form swellings, that is, a series of minute thickenings or 

 varicosities. On the strength of this observation, what 

 we may call a biophysical theory of sleep has been formulated; 

 in the waking state, the neighbouring nerve units are in 

 contact with each other ; transmission of nerve impulses 

 from neuron to neuron is then possible, and the result is 

 consciousness ; during sleep the dendrites are retracted in 

 an amoeboid manner ; the neurons are therefore separated 

 and the result is unconsciousness." 



We might usefully ponder that theory were it not already 

 discredited. 



" Lugaro . . . takes the precisely contrary view. 

 He was not able to discover moniliform enlargements, and 

 his biophysical hypothesis is that the interlacing of dendrites 

 is much more intimate during sleep than during conscious- 

 ness. He therefore explains sleep by supposing that the 

 definite and limited relationships between neurons no 

 longer exists, but are lost and rendered ineffective by the 

 universality of the connecting paths." 



I may be dense but I fail to see in this hypothesis any 

 explanation of the phenomenon of sleep. 



"A more satisfactory histological investigation of -the 

 effect of anaesthetics on nerve-cells was carried out by 

 Hamilton Wright. ... In extreme cases the cells look 

 as though they had undergone a degenerative change, and 

 after eight or nine hours' anaesthesia in dogs, even the nucleus 

 and nucleolus lose their affinity for basic dyes. The change, 

 however, is not a real degeneration, and passes off when the 



