198 INANITION AND MALNUTRITION 



in the anterior horn cells was found in the hibernating hedgehog (Erinaceus) by 

 Jacobsohn ('97) and Levi ('98). The results of Zalla ('10) were negative for 

 the dormouse (Myoxus glis), and inconstant for amphibia (Rami, Bufo, Bombi- 

 nator). Rasmussen and Myers ('16), who reviewed the literature in detail, could 

 find no change in the hibernating woodchuck (Marmota monax). On the other 

 hand, definite seasonal changes in the Nissl substance were found by Biihler 

 C98) in the frog; likewise by Levi ('98) in Rana,Bufo and Zamenis viridis (adder). 

 Chromatolytic and other nerve cell changes during hibernation were observed 

 by Legge C99) in hibernating bats {Vespertilio murinus, Rinolophus ferrum 

 equinum, etc.) ; by Baroncini and Beretta ('00) in Myoxus, Vespertilio and Vesper- 

 ugo; by Marinesco ('05) in Erinaceus; by Cutori ('07, '08) in Testudo graeca; 

 and by Zalla ('10) in reptiles (Lacerta, Zamenis, Tropidonotus). 



The changes in the neurofibrillae during hibernation may be due to the com- 

 bined effect of cold and inanition. Tello ('03) found in dormant lizards the 

 appearance of unusually coarse neurofibrillae in the motor cells of the anterior 

 horn, but not in the brain cells. Cajal ('04 '04a) and Dustin ('06) obtained 

 similar results in leeches and in mammals exposed to cold, especially during 

 fasting. The coarse fibrillae apparently split up again upon the awakening and 

 resumption of activity. Marinesco ('05) noted similar results in young cats and 

 dogs, but no change in the hibernating hedgehog (Erinaceus). Cutore ('07, 

 '08), however, found somewhat different changes in the anterior horn cells of 

 Testudo graeca during hibernation, the peripheral zone of cytoplasm becoming 

 vacuolated and the neurofibrillae more attenuated. Rossi ('10, '10a) noted the 

 thickening of the neurofibrillae in the hibernating adder (Zamenis) and dormouse 

 {Myoxus). Zalla ('10) also obtained the characteristic changes of the neuro- 

 fibrillae in reptiles, and also (less markedly) in mammals (Myoxus). These 

 changes in the neurofibrillae apparently have no definite relation to the changes 

 in the chromophile (Nissl) substance, however, and represent a non-specific 

 reaction to various pathological conditions. The conflicting results obtained 

 by various investigators doubtless depend chiefly upon differences in species, in 

 the technique employed, and in the stage of hibernation studied. 



As mentioned in Chapter X, Rasmussen ('19) found no change in the mor- 

 phology, number or distribution of the mitochondria in the nerve cells of the 

 cerebellum, spinal cord or spinal ganglia in the woodchuck (Marmota monax) 

 after 3 months of hibernation and even after 3 weeks of further inanition upon 

 awakening. 



The experiments of Reinke ('06) on the regeneration of the central nervous 

 system of etherized (fasting) Salamander larvae were mentioned in Chapter X. 

 Rossi ('10, '10a) studied the phenomena of regeneration in the spinal cord of the 

 adder (Zamenis viriflavus) and the dormouse (Myoxus glis) during hibernation. 

 The regenerative process appears to be somewhat retarded, especially in the 

 cold-blooded animals, as shown by the Cajal method. 



(B) Effects of Partial Inanition 



The effects of partial inanition upon the spinal cord have been observed 

 chiefly in protein deficiency (pellagra), vitamin deficiency (beriberi and scurvy), 



