90 APPLIED PHYSIOLOGY 



they themselves inflict upon bacteria. That the spleen 

 is largely concerned in their destruction under normal 

 conditions, or, at all events, in the removal of their 

 debris from the blood, there is little reason to doubt 

 (vide infra). 



The Blood Platelets. There are some who would 

 deny to the platelets the right to be regarded as cellular 

 constituents of the living blood. They have been 

 variously supposed to be simply ' chips ' off leucocytes, 

 portions of extruded nuclei, or a mere ' precipitate ' 

 from the plasma, not found in its natural circulating 

 condition. One of the most recent investigators* of 

 them, however, concludes that they really are cells with 

 a nucleus and protoplasm, and possessed of the power 

 of amoeboid movement, and that they certainly are not 

 degeneration products, but are probably independent 

 elements of the blood. 



On the other hand, Buckmasterf regards them as 

 pure artefacts. In any case, their function is as obscure 

 as their origin, although it has been suggested that they 

 are in some way concerned in the process of coagulation, 

 and their number in the blood appears to be increased 

 in those diseases in which there is a marked tendency 

 to clotting. So far no one has attributed to them any 

 definite role in pathology, and they cannot be considered 

 of much interest to the clinician. 



* Deetjen, Virchow's Archiv, 1901, clxiv. 239. 

 t 'The Morphology of Normal and Pathological Blood' (John 

 Murray 1906), p. 132. 



