EFFECTS ON THE VISUAL APPARATUS 21 5 



nucleus in many cells is irregularly shrunken or pycnotic. Lodato thinks it 

 remarkable that vision is not more affected by these changes in the ganglion 

 cells. 



Cattaneo ('oo) studied the functional and chemical changes (which are 

 slight) in the eyeballs of 3 rabbits. One eyeball (control) was enucleated before 

 complete inanition of 6-1 1 days. Kammerer ('12) observed that in fasting 

 Proteus anguinus the eye pigment is reduced and absorbed, which recalls a 

 similar process in certain invertebrates (planarians and nemertine worms) as 

 mentioned in Chapter III. 



Kornfeld ('22) studied the effect of the plane of nutrition upon the rate of 

 mitosis in the corneal cells of the larvae of Salamandra maculosa, which were 

 richly fed after various periods of total inanition. The total number of mitoses 

 per cornea drops to about 4, after total inanition for 3 or 4 days. Upon refeed- 

 ing, the number does not change for 4-5 days, then increases rapidly to a 

 maximum of about 400 after 6-14 days of refeeding. While nutrition is a 

 condition necessary for cell division, Kornfeld thinks that hormones or other 

 stimuli may also be necessary factors. 



(B) Effects of Partial Inanition 



The types of partial inanition affecting the visual apparatus include chiefly 

 deficiencies of protein (edema and pellagra), of salts (rickets) of vitamins (xero- 

 phthalmia, scurvy) and of water. 



Protein Deficiency. — In Chapter V, evidence was cited to indicate that the 

 edema frequently occurring in connection with famine and similar malnutri- 

 tional conditions is in many cases probably due chiefly to protein deficiency, 

 though often associated with other dietary defects. Lesions of the visual appa- 

 ratus frequently occur in connection with the edema. Maynard ('09) observed 

 a slight cloudiness of the cornea, with dimness of vision and evidences of increased 

 intraocular tension in 20 cases of "epidemic dropsy." Budzynski and Chel- 

 chowski ('i6)mentioned night-blindness as almost constant, generally preceding 

 the edema. Schittenhelm and Schlecht ('19) likewise noted frequent hemer- 

 alopia and xerosis in such cases. The literature is reviewed by Maver ('20). 



In pellagra (also probably due primarily to protein deficiency), ocular lesions 

 may occur. According to Marie ('08, '10), these include conjunctivitis with 

 pterygium and hemeralopia, sometimes pigmentary retinitis. 



In rickets (deficiency of phosphorus or calcium and of antirachitic vitamin), 

 according to Juaristi ('19), the eyes are more round and show more of the sclera, 

 associated with changes in the fundus. In experimental rickets in rats on diets 

 deficient in vitamin A and phosphorus, Shipley, Park, McCollum and Simmonds 

 produced both xerophthalmia and rickets. The addition of phosphates pre- 

 vents the rickets, but not the xerophthalmia (which will be considered later). 

 In albino rats with experimental rickets, Jackson and Carleton ('22, '23) found 

 an increase in the weight of the eyeballs (Table 2), amounting to over 4c per 

 cent in the group with severe rickets. Possibly this increase in weight may be 

 related to that above mentioned as occurring in young rats with general growth 

 retarded during incomplete total inanition. 



