78 THE VITAMINS 



perature, and difficulties in respiration. In this phase only were low values 

 obtained for oxygen consumption. In most cases after the body temperature was 

 raised to normal by placing the animal in a warm place for about two hours, the 

 oxygen consumption rose to a nearly normal level and there was a marked 

 although temporary improvement in the condition of the animal — such as noted 

 by Peters (1924), and Kinnersley and Peters (1925) in the case of pigeons ("heat 

 cure"). This is thought to demonstrate conclusively that the oxidative mechanism 

 is not damaged in vitamin B deficiency. 



It was next shown that the figures for rectal temperature, body weight, and 

 oxygen consumption of rats fed a complete artificial diet plus 5 per cent yeast 

 extract, in amounts corresponding to the estimate of what would have been 

 voluntarily consumed of the vitamin B deficient ration, were strikingly similar 

 to those obtained with rats of the same initial weight receiving a vitamin B-defi- 

 cient ration ad libitttm, and that in the smaller rats of the first group, there was 

 eventually the same sharp decline in weight, rapid fall of temperature and oxygen 

 consumption, followed by death, invariably resulting on the vitamin B deficient 

 diet. Starving rats and rats receiving only yeast were likewise shown to maintain 

 their body temperature and oxygen consumption until shortly before death. "To 

 our minds it seemed clear from these results that the lowered metabolism and 

 body temperature observable during the last phase of the condition resulting 

 from deficiency of vitamin B were merely indications that the animal was dying 

 and that the immediate cause was general starvation." 



This conclusion was confirmed by the striking similarity found by Woollard 

 (1927) in the histological appearance of the nerve tissues of the rats deprived of 

 all food and of vitamin B alone, although the lesions were more marked in the 

 latter case. The only changes noted were in the intermuscular medullated motor 

 and sensory nerves and their endings, these changes subsiding rapidly at a little 

 distance from the muscles. The sympathetic and central nervous systems showed 

 no abnormal anatomical changes. 



That many of the phenomena of polyneuritis in pigeons may also be traced 

 to starvation, as suggested earlier by McCarrison from qualitative studies, was 

 demonstrated by Kon and Drummond (1927) in a later paper of the same series. 

 In order to separate the eflfects of inanition from those which might be due more 

 directly to the vitamin deficiency itself, each of a group of eight pigeons was 

 matched as closely as possible in weight and age with another pigeon to serve as 

 control. The first group received a modified artificial vitamin B-free diet of the 

 type used by Randoin and Simmonet. Each of the pigeons of the second group of 

 matched controls was forcibly fed the same quantity of food that the corresponding 

 pigeon had received the previous day plus 1 gram of yeast extract (marmite). 



The records of body weight, food consumption, and, in the later stages of 

 the experiment, body temperature were strikingly similar for corresponding 

 pigeons in the two groups. An initial loss in body weight, attributed to lack of 

 appetite during adjustment to confinement in separate cages, followed by slight 

 gain and then a gradual loss, was characteristic of the pigeons in both groups. 

 At about the beginning of the fourth week there was sometimes a partial but 

 transient recovery of appetite. A progressive fall in body temperature occurred in 

 both groups up to the onset of acute symptoms, when there was a rapid drop in 

 temperature in the five pigeons in the first group which developed typical poly- 

 neuritic symptoms. Four of the five pigeons developing acute symptoms recovered 

 from the first convulsive seizures without being treated, and with recovery there 

 was a rise in temperature from the low level during the attack. "It seems fair 

 to assume that the thermal changes occurring in pigeons during vitamin B defi- 

 ciency are two-fold : firstly, a progressive decrease which is most probably due 

 to insufficient food intake, and secondly, a profound and rapid fall manifesting 

 itself in the course of a few hours and associated with the onset and gravity of 

 acute nervous symptoms. There seems a possibility that this phenomenon is more 

 directly related to vitamin B." 



Histological examination by Woollard of pigeons from the two groups showed 

 similar changes in both groups attributable to the wasting resulting from starva- 

 tion. No relation could be traced between the occurrence of acute nervous symp- 

 toms and degenerative changes in the nerves. "It can not be sufficiently emphasized 



