460 Messrs. W. Cramer, A. H. Drew, and J. C. Mottram. 



Effect of Vitamin A Deficiency on the Leucocytes. — This subject has already 

 been dealt with in a previous paper. There are no constant or characteristic 

 changes. In the final stage, when infection has supervened, there is usually 

 a great increase in the absolute number of polymorphonuclear cells. The 

 lymphocytes show, as a rule, no more than a slight diminution, which contrasts 

 sharply with the profound lymphopenia observed when the water soluble 

 vitamin is withheld. We have already stated that a lymphopenia may also 

 occur in the vitamin A deficiency when the acute effect has been produced 

 and the animals are in a very poor state of nutrition. 



There appears to be a change in the number of the polymorphonuclear 

 leucocytes, in the sense that the nucleus is less lobulated in the animals 

 suffering from the vitamin A deficiency. To establish this fact fully would 

 require a very extensive series of observations which we do not propose to- 

 undertake. "We only refer to it here because it may afford an explanation of 

 the statement that the so-called " Arneth index " (number of lobules of the 

 polymorph nucleus) of tuberculous individuals is higher than that of normal 

 individuals. The explanation may possibly be found in the fact that the high 

 Arneth index of the tuberculous individual is due to his dietary treatment, 

 the diet being very rich in the fat- soluble vitamin. 



Effect of Vitamin B Deficiency. — Some observations were made on rats kept 

 on a diet free from vitamin B, but containing an ample supply of vitamin A. 

 The results which are given in the following Table show that when the 

 vitamin B is absent and vitamin A present the platelets do not diminish to- 

 any extent, even at a time when the temperature has become very distinctly 

 subnormal, and indicates an advanced stage of the deficiency : — 



Effect of B Deficiency. 



No. of 

 rat. 



Weeks of 

 B deficiency. 



Temperature. 



Difference 

 of initial 

 weight. 



Bed cells. 



Platelets. 



414 



5 



° 



35 -7 



Off 



11,560,000 



980,000 



415 



5 



35-2 



Off 



9,920,000 



640,000 



416 



5 



Below 35 



-Off 



10,000,000 



1,200,000 



In the very last stages of this deficiency we have occasionally obtained low 

 figures for the platelets. But here a technical difficulty arises, because it is- 

 difficult in that condition to obtain a free flow of blood when the tail is cut. 

 This is, however, essential, since the blood platelets tend to stick to the tissues 

 of the wound and disintegrate there, when the blood is oozing out slowly. 



