647 



corpuscles. The slrongly sensitized red cells mostly 'work less (|niekly ; 

 the scrum of the rabbits oets a lower titre ! But on a whole the 

 difference is not great, generally smaller than was found by Sachs 

 and VON Düngkrn. 



The weakly sensitized red cells are generally not inferior to tho 

 nonsensitized as to immunisation power (in one series they even 

 worked somewhat more quickly); the final result is either the same 

 or a little less. In one series, with the treatment with red cells of 

 ox appeared the danger of intravenous injection of sensitized cor- 

 puscles : a number of rabbits died of anaphylaxis. As a rule however, 

 they could well stand the injections. I made one series of experi- 

 ments with injection (intraperitoneal) of sensitized and non sensitized 

 red cells of ox into rabbits, which a fortnight ago had alread}' 

 had a first injection of red cells of ox, and which now all had an 

 equal titre (Vsoo)- The rabbits that were injected with strongly sensi- 

 tized corpuscles all five died of anaphylaxis ; of those that were 

 injected with weakly and nonsensitized corpuscles three died of five 

 resp. two of five of anaphylaxis. 



So I did not continue those experiments. 



December 1913. Laboratory of Patk. Anatomy, Amsterdam. 



M Physiology. — "On the relation between the qiiantity of brain 

 and the size of the body in Vertebrates". By Prof. Eugene 

 Dubois. (Communicated by Prof. H. Zwaakdemakerj. 



(Communicated in the meeting of November 29, 1913). 



It is obviouf^ that, in general, in different species of animals, 

 the relative quantity of brain must be a measure for the degree of 

 the organisation of the nervous system. There are however still 

 other factors influencing the quantity of brain. In the first place 

 the size of the body, but especially also the age and the individual 

 deviations, further possible deviations caused by the living of the 

 animal out of the state of nature. 



Of these factors the three last mentioned ones can easily be 

 excluded, the age, by choosing only full grown animals for compa- 

 rison, the individual deviations, liy taking averages, or (which in 

 some cases may be preferred) by choosing individuals representing 

 the norm. Then remains still the factor of the size of the body. 

 Its influence cannot be appreciated by simply calculating the relative 

 quantity of brain. For a long time it has been known already that 



