THE LIVING SUBSTANCE. 49 



far more fluid than endosarcal areas, although it usually is seen 

 in a more viscous state. 



One interesting unstable area of structural reduction which 

 I think has not yet been described, was seen as a variably 

 present and fluctuating area surrounding the nucleus in 

 Amoebas. Very finely vesiculate, often passing into true 

 optical structurelessness, when it had an effect of brownish or 

 yellowish hue and was of a dense and peculiar appearance, this 

 viscid mass adhered to the nucleus and was carried along with 

 it, as the endosarc rolled hither and thither. Less transparent 

 and also far less refractive, though quite as dense nearest the 

 nucleus, it reminded one much of the "achromatic" areas in 

 embryonic masses. 



Its amount was greatly varied from minute to minute, some- 

 times being at least one-sixth the width of the cytoplasmic 

 area, at others merely a sticky-looking stratum close to the 

 nucleus, as if the cytoplasmic pellicle were unevenly aug- 

 mented. Whatever its thickness, it swept along with the 

 nucleus, holding its place as an almost solidly attached sub- 

 stance while its outer portions were drawn out as threads and 

 viscid-looking processes in the cytoplasmic flow over its sur- 

 face, so that it looked somewhat like a caged Heliozoan in 

 closest physical union with the surrounding fluid alveolation. 

 No special life phenomenon was seen to be correlated with the 

 presence of this area. 



It is not only at time of initial formation of ectosarc that the 

 phenomenon of structural reduction is seen. In ectosarc long 

 formed and quite stably persistent through long periods, and 

 in ectosarcal organs and areas, similar redistribution of the 

 elements takes place at times, changing the physical form of 

 the substance locally or throughout the whole area from a 

 perhaps marked and uniform structure of Biitschli, or finer 

 forms, to others progressively finer until a point of actual 

 optical structurelessness is reached. From this state redistri- 

 butions may later bring before us again a true structure of 

 Biitschli, not the former one but another, in which it is more 

 than likely not one particle of the elements holds its initial 

 relative position as to the others or as to the whole mass. 



