278 The'fStructure of Colored Blood-Gorjpuscles. 



216 millionths of an inch, or .01005 and .00548 Mm.— were 

 present in the same field of one drop. 1 



Berchon and Perrier 2 state that the colored blood- 

 corpuscles of the foetus and the newly-born are on an aver- 

 age smaller than those of adults. The extremes given are 

 minimum .0031 to ,0062 Mm. and maximum .0091 to .0093 

 Mm.; but they do not mention that the extremes occurred in 

 one and the same case. More recently, Perrier 3 measured 

 blood-corpuscles of 35 individuals of different ages, and 

 found that those of .010 Mm. were very frequent in the first 

 days after birth, while later they occurred much more rarely. 

 After the first year, blood-corpuscles measuring .0093 Mm. 

 were rarely present in greater proportion than 10 in a hun- 

 dred ; and in adults often absent. Such of .0043 Mm. oc- 

 curred most often in the aged and in children. The diameter 

 of the great mass at every age varies from .0050 to .0087 Mm.; 

 within these limits, those of .0075 Mm. are most frequent and 

 never absent. The form of the smaller is more or less 

 globular ; the larger are flattened. 



According to Hayem^ the red blood-corpuscles in the 

 newly born are much less uniform in size than in adults ; 

 corpuscles larger than the largest and smaller than the 

 smallest adult corpuscles occur comparatively often. The 

 size varies between .00325 and .01025 Mm. Hayem also 

 calls attention 5 to the still smaller ones — measuring only .002 

 Mm. — which he considers young and growing blood- 

 corpuscles, so called hsematoblasts. He asserted having ob- 

 served all transition sizes between these and the largest. He 



(1) " The Application of Photography to Micrometry, with special reference to the 

 micrometry of blood in criminal cases." Transactions of the American Medical Associa- 

 tion, vol. XXVH. (1876), p. 303-315. 



(2) " Note sur les globules du sang chez le foetus." Bordeaux medical., p. 123 and 237 ; 

 Canstadt's Jahresbericht for 1875, 1., p. 46. 



(3) " Sur les variations du diametre des globules rouges du sang dans l'espece humaine, 

 au point de vue de l'expertise legale." Compt. rendus, torn. 84 (1877), No. 24, p. 1404. 



(4) Des caracteres.anatomiques du sang chez le nouveau-n6 pendant les premiers jours de 

 la vie." Compt. rendus, torn. 84 (1877), p. 1166. 



(5) " Sur la nature et la signification dee petits globules rouges du sang." Ibid, No. 22 

 p, 1289. 



