132 



PHARMACEUTICAL BACTERIOLOGY 



ally there are two or more smaller vacuoles, sometimes as many as twenty 

 or thirty, again there may be one comparatively large vacuole and two or 

 more smaller vacuoles. 



5. There is a striking similarity between the younger sphaerocytes as 

 above described and the resting or encysted forms of amebae. In fact 

 so striking is this resemblance that it was at first supposed that they 

 might be stages in the life history of -certain amebae, but further obser- 

 vation proved this supposition erroneous. Sphaerocytes disappear with 

 the advent of decomposition whereas amebae thrive in the presence of 

 decaying substances. 



6. The colorless younger sphaerocytes are generally without nuclei; at 

 least none could be detected by the usual staining methods. 



FIG. 46. Amebo-sphaerocytes of the green tomato. A, actively motile forms with 

 chlorophyll granules. B, actively motile forms without chlorophyll granules. C 

 encysted amebo-sphserocytes with chlorophyll granules. D, encysted forms without 

 chlorophyll granules. 



The sphaerocytes are very abundant in the mucilaginous layer enclosing 

 the seeds of the tomato (Schleimhulle), where they occur in all stages 

 of development, ranging in size from the very limits of microscopic iden- 

 tification (about one micron in diameter) to mature mucilaginous tissue 

 cells (275 microns in diameter). They originate in the cell plasm and are 

 soon extruded from the cell plasm whereupon they continue an independent 

 existence within or without the mother cell. The extra-cellular forms no 

 doubt make their escape from the cell by way of the pores of the cell- wall. 

 Some may be derived from intercellular plasmic threads. 



Occasionally groups or clusters of sphaerocytic pulp cells occur in cer- 

 tain areas of the tomato pulp, more especially near the epidermal layers. 

 It would appear that under ordinary or usual conditions the sphaerocytes 



