44 CALIFORNIA ACADEMY OF SCIENCES. [ 3 d Ser., 



probably not ten per cent., and these appear to be full of 

 large and small vacuoles. The spheres become less dis- 

 tinct, finally diffusing one into the other, and no longer 

 responding to the stains. They become more transparent 

 as the plasma evidently becomes less dense. The interior 

 spheres are the first to disappear from view, the centro- 

 somes with them. In the last stages of its existence the plas- 

 mocyte resembles a large diffuse blood plate. Fig. 78 rep- 

 resents a dissolving plasmocyte with both large and small 

 vacuoles stained with Ehrlich-Biondi. Judging from the 

 few which thus decay, I conclude that the life of a plasmo- 

 cyte is fully as long as that of a nucleated blood cell, and 

 probably much longer. 



Adhesive Nature of the Cytoflasm. — Every one who has 

 observed the fusiform corpuscles has remarked upon the 

 adhesive nature of the outer cytoplasmic layer. Frequently 

 a number of such corpuscles are seen adhering together, 

 forming irregular discs. The plasmocytes act exactly in 

 the same way. Not only are they found joined or attached 

 to each other but frequently they are also seen adhering to 

 the margin of the plasmocytoblasts. It is not always 

 easy to determine when we have before us a free plasmo- 

 cyte whether it is simply adhering to the cytoplasm of a 

 plasmocytoblast or is separating from it. The continuation 

 of the two outer .spheres must be the criterion of this, 

 though in the first stage of the plasmocyte the difference 

 cannot be very great. If there is any large amount of 

 granosphere yet in position at the apex of the nucleus, and 

 if this granosphere is conelike and contains a microcen- 

 trum, we may assume, with great probability, that the ad- 

 hering plasmocyte is really only adhering and not in the act 

 of separating. After all the plasmocytes have separated 

 from the plasmocytoblast there often remains a thin crescent 

 of granosphere close to the nucleus, but this crescent does 

 not contain any parts of an archosome, therefore cannot 

 produce other plasmocytes. 



