THE BLOOD. 85 



It would be a point of much interest to determine whether 

 arterial or venous blood contains the greatest number of 

 blood corpuscles. The experiments which have hitherto 

 been made with the view of determining this question are 

 most unsatisfactory, and contradict each other. 



MODIFICATIONS OF THE BLOOD CORPUSCLES THE RESULTS 

 OF DIFFERENT EXTERNAL AGENCIES. 



Peculiar Modification the Effect of commencing Desiccation. 



If the red corpuscles be examined a few minutes after their 

 abstraction from the system, in a drop of blood which has 

 been spread out between two plates of thin glass, it will be 

 seen that many of them, and especially those which are situ- 

 ated near the margin of the drop, present an appearance very 

 different from that which belongs to them in their ordinary 

 and natural condition. They now no longer exhibit the 

 flattened form with the central depression, but have become 

 converted into little spheres, the surface of which, instead of 

 being smooth, is now rough and tuberculated. (See Plate I. 

 Jig. 5.) Blood corpuscles thus changed have been compared 

 to mulberries in appearance. This alteration is supposed by 

 Donne to depend upon commencing desiccation, and to arise 

 from deficiency of serum, the mulberry-like globules being 

 but imperfectly bathed in that liquid. No very satisfactory 

 explanation of the exact nature of the change has as yet 

 been given. MM. Andral and Gaverret * suppose that the 

 mammillated appearance of the corpuscles arises from the 

 adherence to the surface of the globules, of a number of the 

 exceedingly minute molecules of the fibrin ; this explanation 

 is probably more ingenious than correct. If a number of the 

 altered globules be carefully and closely examined, it will be 

 remarked that they do not all exhibit precisely similar ap- 

 pearances ; that in some globules, for instance, it will be 

 observed that the contour is but slightly broken or indented, 

 that in others the indentations of the surface are more con- 



* Essai d'Hemalogie Pathologique, par G. Andral, page 23. 



