378 CARNEGIE INSTITUTION OF WASHINGTON. 



It has been surprising to us, as well as to other investigators in this field, 

 to find that animals which have grown splendidly on rations consisting of 

 purified proteins, fat, carbohydrate, and salt mixtures, together with fats 

 bearing vitamine A and yeast as a source of vitamine B, almost invariably 

 fail to breed, although their general appearance indicates that they have 

 developed normally. Examinations made in collaboration with workers in 

 Professor Harrison's laboratory at Yale University have shown, however, that 

 the gonads of both the male and female animals as well as the oestrous cycles 

 of the latter are extremely abnormal. An extensive study of these abnor- 

 malities is planned. It is interesting to note that small additions of egg- 

 yolk, and probably other naturally occurring foods, to the diets suffice to 

 avert sterility. An opportunity to investigate the relation of the diet to the 

 development and functions of the gonads is thus presented. The preliminary 

 observations which we have made may help to explain some of the anomalies 

 of reproduction frequently encountered in the case of domestic animals. 



Doctors A. M. Yudkin and R. A. Lambert, of the Yale School of Medicine, 

 have studied the pathology of the eye in relation to the ophthalmia which we 

 first described several years ago in the case of rats fed on diets deficient in 

 vitamine A. These investigations, made on animals which we prepared for 

 them, showed that the changes in the eye do not begin in the cornea, but have 

 their origin in the lids. In this respect they resemble the severer types of 

 acute and chronic conjunctivitis which are frequently complicated by corneal 

 injury, with infection, and ulceration of this structure. They also found that 

 the lacrimal glands may be the seat of a marked pathological change, either 

 degenerative or inflammatory in nature. Such changes are much more marked 

 in xerophthalmic than in normal rats. Variation in the size, form, and stain- 

 ing properties of the cells are frequently seen and are probably referable to 

 functional disturbances related to the ophthalmia. This may account for 

 the drying of the cornea in the later stage of xerophthalmia. 



We have also attempted to ascertain whether a relative deficiency of vita- 

 mine B will hasten the appearance of ophthalmia on a diet also devoid of 

 vitamine A. The onset of visible signs of this disease is, as a rule, somewhat 

 more rapid under these conditions, and the increase in the supply of either 

 vitamine will improve the defect for which its lack is specifically responsible 

 without benefiting the animal noticeably in respect to its other deficiency. 

 Thus, an intake of an adequate supply of vitamine B will not relieve the eye 

 symptoms, nor will the mere addition to the diet of vitamine A, in the form of 

 cod-liver oil, promote growth, although careful ophthalmological examination 

 may show that the ophthalmia is completely cured. 



The elaborate chemical fractionation of the alfalfa plant as a type of living 

 leaf cell has incidentally furnished a variety of products which may be of 

 interest in the study of the distribution of vitamines in plants. Preliminary 

 investigations, which we have already undertaken, promise to give some 

 interesting information and may, perhaps, pave the way for a better under- 

 standing of the chemical character and behavior of some of the vitamines. 



A study of the fractions obtained from the green alfalfa plant has been 

 made, attention being chiefly devoted to the water-soluble nonprotein- sub- 

 stances. The purpose of this investigation has been to find methods whereby 

 the water-soluble constituents of the juice could be separated into groups 



