68 



J. Lindhard. 



simultaneously with and probably as the result of increased pulse- 

 pressure. 



It follows from this, that the number of leucocytes must vary 

 in the course of the day, and that the number on different days can 

 only be compared when the samples are taken at the same time of 

 day, after that the day has been passed in the same manner. The 

 procedure of Kjer-Petersen is therefore the correct one, namely, 

 to take the blood samples in the morning before food has been 

 taken, if the variations are to be studied from day to day, as it is 



J L 22/5 08 



J L 'V5 08 



J L Э '0/1 07 



J L '°-'У1 07 



Fig. 1. 



easiest at this time to obtain uniform material. Whether we should 

 likewise obtain the lowest values at this time, as Kjer-Petersen 

 maintains, is however another question. In 5 day-curves derived 

 from self observations I have only in 1 case found the lowest value 

 in the morning (the difference between this and the next is here 

 very small), in the 4 other cases the minimum falls in the second 

 series, 2 hours later; this is also the case in 2 day-curves from 

 another person. In a third individual the conditions were more 

 irregular. In his case the lowest value was found in the morning 

 in one instance, in another in the second series, whilst in two in- 

 stances the minimum occurred later in the day. 



