370 THE AMERICAN MONTHLY [Dec, 



4. The observations that fjlatelets arise from red 

 blood corpuscles had already been made. L, Elsberg 

 after the treatment of red blood corpuscles with a 40 to 

 50 per cent solution of bichromate of patash. (Annals 

 of the New York Academy of Sciences Vol. 1875.) 



He says, " An indentation at the periphery of the red 

 blood corpuscles is due to locally limited contraction of 

 the net work in the interior of tHe corpuscles. Contrac- 

 tion of the living matter in one part of the periphery will 

 bring about a protusion of the flap at another, the flap 

 being bounded by the layer of the corpuscle. Segmental 

 contraction of the net work will produce a rupture of 

 the outer layer of the corpuscle, with projection of a 

 pediolated granule or knob, formerly a part of the in- 

 terior network ; contraction will be followed by the rup- 

 ture of the pedicle and the production of either so called 

 detritus, or small granules, or when the protuded knob 

 is larger, or has become swelled, of a pale grayish disk. 



L. Elberg adds to this remarkable observation for 

 which he never has been given credit, the following re- 

 mark. " The peculiar corpuscles believed to be charac- 

 teristic of syphilis by Lostorfer, and proved by Strieker 

 to be present in the blood of individuals broken down 

 by that and various other diseases are nothing but such 

 disks, i. e., portions of the colorless blood corpuscles 

 protruded from the interior, detached and more or less 

 swelled. As persons in low states of health have a re- 

 latively small amount of living matter in the same bulk, 

 or in other words, only a delicate net work within a pro- 

 toplasmic body, or plastid, the so called cell, such net 

 work suspended in a relatively large amount of fluid 

 can much more easily contract and bring about a rupture 

 of the outer layer, than in the case of healthy persons 

 within whose plastids there is relatively less room for 

 contraction to take place." 



All the named observations explain why a platelet has 



