THE BLOOD. 



241 



cles of any given specimen of blood are those of a human being or of some 

 other mammal, a knowledge of the size of the corpuscles is a matter of 

 medicolegal as well as of physiologic interest. Though the differences in 

 size are slight, yet it is possible for skilled microscopists, when examining fresh 

 blood, to make a diagnosis between the corpuscles of man and those of the 

 domesticated animals, with the exception, perhaps, of the guinea-pig. The 

 diagnosis of the corpuscles of dried blood which have been altered by the 

 action of various external agents, even though capable of a certain degree 

 of restoration, is most difficult, and should not be attempted in criminal 

 cases without large experience in microscopy, in measurements and methods 

 of preparation of all kinds of blood-corpuscles, and a proper conception of 

 corpuscular forms and sizes. In the following table the average results of 

 the measurements of the corpuscles in different classes of animals are given 

 (abstracted from Formad's compilation) : 



Gulliver 



Inch Mm 



Wormley 



Inch | Mm. 



C. Schmidt 

 Mallinin 



French Medi- 

 colegal Soc. 

 Welcker 



Formad 



Inch Mm. Inch Mm. Inch Mm. 



Man 



Guinea Pig 



Dog 



Rabbit 



Ox 



Pig 



Horse 



Cat 



Sheep 



Goat 



,3200 o 

 3538.0 



,3607 o. 

 .4267 o. 

 ,4230 o. 

 ,4600 o. 

 .4406 o. 

 .5300 o. 

 .6366 o. 



0079 



0071 

 0071 

 0070 

 0060 

 0060 

 0057 

 0058 

 0048 

 0040 



.32500 



.3223 o 

 .3561 o 

 .3653 o 

 .4219 o 

 .4268 o 

 .4243 o 



.4372 O 



.4912 o 

 .6189 o 



,0078 

 0079 

 ,0071 

 .0070 

 ,0060 

 .0059 

 0059 

 ,0058 

 ,0031 

 0041 



.3300 

 .3300* 

 .3636 

 .3968 



4354 

 .4098 

 .4464 



4545 

 .5649 

 .6369 



0.0077 



0.0077 I 



o .0070 



0.0064 



0.0058 



0.0062 



0.0057 



0.0056 



0.0045 



o . 0040 



3257 O 



.3213-1-0 



.3485 o 



.3653 o 



4545 o 



.4098 jo 



4545 b 



.3922 o 



.5076 jo 



5525 JO 



.0078; 



.0079! 

 .0073! 

 ,0069 

 .0056 

 .0062 

 .0056] 

 .0065 . 

 .0059 i 

 .0046 i 



3200,0 



3400 O, 



.35800 

 3662 o, 

 ,4200 o , 

 4250:0, 

 431!' 



0079 

 0075 

 0071 

 0069 

 0060 

 0060 

 0059 



500050.0051 

 6100 o. 0042 



In birds, reptiles, and amphibians the corpuscles are larger than in 

 mammals, are oval in shape, and nucleated. (See Figs. 103 and 104.) 

 As the scale of animal life is descended the corpuscles increase in size, until 

 in Proteus and Amphiuma the long diameter at- 

 tains an average length of 0.058 mm. and 0.077 mm. 

 respectively. In fish the corpuscles are smaller, 

 oval, and nucleated, with the exception of the 

 lamprey eels, in which they are circular, biconcave, 

 and nucleated, though the nucleus is generally con- 

 cealed in the peripheral portion of the corpuscle. 

 As in these animals the corpuscles are almost twice 

 the size of the human red corpuscles, they can, not- 

 withstanding the similarity of shape, be readily dis- 

 tinguished from them. 



The Function of the Red Corpuscles. The 

 red corpuscles, by virtue of the capacity of their 

 contained hemoglobin for oxygen absorption, maybe 

 regarded as carriers of oxygen from the lungs to the tissues, and therefore 

 important factors in the general respiratory process. The size as well as t he 

 number of the corpuscles in different classes of animals appears to be directly 

 related to the activity of the respiratory process. In those animals in which 

 the corpuscles are small and numerous and the total superficial area large 



FIG. 103. FIG. 104. 

 AMPHIBIAN COLORED 

 BLOOD-CORPUSCLES. Fig. 

 103, on the flat; Fig. 104, 

 on edge. (Landois and 

 Stirling.) 



* Masson. 

 16 



f Woodward. 



