Vedder 94 is of the opinion that the antineuritic vitamin is a building stone which is essential for the metabolism of the nerve tissues, basing his opinion on the following facts:

1. If the supply of this vitamin is out down by feeding exclusively on poiiahed rice, changes in the structure of the nerve fibres of fowls may be demon strated after only seven days on such a diet. The evidence of incipient degeneration at such an early date appears to indicate that a certain amount of this vitamin is constantly necessary in order to maintain the nervous system in a healthy condition.

2. The nerve cells from the cord of fowls suffering from polyneuritis gal-linarum present changes very similar to those demonstrated in the nerve cells of birds that suffer from fatigue as the result of long flights.

3. Fowls suffering from polyneuritis may be completely cured within a few hours by the administration of the vitamin obtained from rice polishings.

McCollum and Simmonds95 suggest that polyneuritis symptoms in an animal are due to progressive degeneration of the motor cells of the spinal cord. Even at the acute stages, however, there are normal cells which are capable of functioning if sufficiently stimulated, and consequently any substance which supplies the necessary stimulus through its pharmacological action will induce at least temporary relief. Cramer, Drew and M or tram 95a have pointed out that in avitaminosis there is extreme reduction of the lymphocytes, both in the lymphoid structures and in the blood, and that this condition is also produced by exposure to X rays and radium. Moreover these agents, if used in sufficient amount produce other effects very similar to those of avitaminosis, loss of weight, degeneration of the seminiferous tubules of the testes, and ultimate death. They suggest that all these agencies may exert a selective action on the lymphoid tissue and that this tissue is more important in the nutrition of animals than has been supposed.

93 See p. 173, Vezar and Bogel.

94 Vedder, Proo. 2nd Pan Am. Sci. Cong. 8eo. 8, pt. 2, p. 27. 95 McCollum and Simmonds, J. Biol. Chem. 33, 56, 1918. 95a Cramer, Drew and Mortram, Lane. 1921,1, 903.

Lumiere96 ascribes the death of pigeons fed on polished rice to starvation from lack of appetite, the result of stagnation of the ingested rice from lack of secretions to aid in digesting it and passing it along the alimentary canal. He concludes that the special function of the vitamins is the stimulation of the gastrointestinal motor functioning and the secretory functions of the glands with an external secretion. Without vitamins the digestive glands cease to function, and the animals succumb to loss of these secretions although their digestive tract may contain abundance of nourishment. On the other hand, animals will succumb if deprived of sufficient nourishment to keep them in health, even if there is abundance of vitamins present. About one-third of the animals under observation developed in addition to the usual symptoms of starvation the paralytic and cerebellar disturbances which have been regarded as characteristic of vitamin deficiency. Prompt recuperation when vitamins are supplied after deficiency disease has developed testifies to their stimulatory power on the digestive glands.

The special development of the cerebellum in birds to control orientation in flight requires an extra amount of nourishment, so when nourishment is shut off by lack of vitamins the cerebellum suffers first and the cerebellar symptoms are the first to appear. In support of his view Lumiere states that pigeons develop polyneuritis as quickly on a starvation diet but with excess of vitamins as they do on the same diet without vitamins. When rice is supplied to these pigeons in sufficient amounts they recuperate as rapidly as those which have developed polyneuritis through feeding on polished rice do when supplied with vitamins. The disease produced by feeding a ration of 4 g. of polished rice, 2 g. glucose, and 1 g. brewers' yeast per day was cured by increasing the amount of polished rice. On the other hand, Karr97 concludes from the fact that the utilization of nitrogen in the digestive tract is not affected by lack of B that the secretions of the glands associated with digestion and absorption are in no way dependent upon the supply of vitamins.

Uhlmann 98 found that the administration of vitamins to cats and dogs, either subcutaneously, intravenously, or by the mouth, caused a marked stimulation of the salivary, sweat, gastric, and other glands, which is inhibited by atropine. From these observations he concluded that the vitamins in the food play an essential part in the processes of digestion and metabolism through their stimulatory action on glands producing external and internal secretions.

96 Lumiere, Bull. acad. med. Paris, 83, 310; 84, 274, 1920; Par. Med. 10, 474, 1020; J. Am. Med. Assoc. 74, 1607, 1020. 97 Karr, J. Biol. Chem. 44, 277, 1020. 98 Uhlmann, Zeitsch. Biol. 1018, 68, 410-456.

The work of Funk and Douglas, McCarrison, and Emmett and Allen, showing the marked degenerative changes in the glands of internal secretion, appear to indicate a very definite relation between these glands and the vitamins, and this is further suggested by Swoboda's 99 findings that B is present in large quantities in most of the organs of internal secretion which are of developmental importance, but in much lower concentrations in other organs, with the exception of the liver and kidney. Hopkins 100 has given it as his opinion that there is increasing probability that the function of the accessory food factors is connected with the stimulating of the internal secretions. In the light of our constantly increasing knowledge of the inter-relation between the internal secretions and their immense importance in metabolism, the dependence of these glands upon the vitamins, could such be proved, would be entirely sufficient to account for all the numerous symptoms which have been noted as resulting from vitamin deficiency.

Accepting this hypothesis provisionally we are led to inquire whether there is anything in the nature of the vitamins which might explain their effect upon the secretory organs.