106 J. W. JENKINSON. 



All these facts point to their being related to Crato's 

 physodes. They are also partially soluble in absolute alcohol 

 and ether^ though they do not entirely disappear in these 

 liquids as Crato^s physodes do. If killed in 30 per cent, alcohol 

 they only contract slightly, at the same time losing much of 

 their staining capacity, and refusing to show the characteristic 

 reaction with vanillin, so that the phloroglucin is apparently 

 dissolved out. By staining the fixed material with iodine-green 

 fuchsin or methylene-blue acid fuchsin, the ground substance of 

 the physodes appears kyanophilous ; it also takes up hsematein- 

 ammonia as readily as the chromatin and nucleoli, but can be 

 destained with alum more readily than these. 



In the living cell the physodes often lie in rows, sometimes 

 very closely together (Fig. D, 7), which rows have apparently 

 an oscillating movement. Along the protoplasmic threads, also, 

 which connect the separate energids of the cell, the single 

 physodes, as well as the rows, are seen to move. This may be 

 readily observed by intra vitam staining (Fig. D, 5) with a 

 very dilute aqueous solution of methylene blue ; if too strong a 

 solution be used the protoplasm becomes vacuolated, many of 

 the deeply stained physodes being ejected into the vacuoles, 

 where, together with the crystals of calcium oxalate, they are 

 seen to execute the so-called Brownian movements, evidence 

 that in the cyst, at any rate, they are of a more or less per- 

 manent consistence. The cell sap in the vacuoles becomes 

 at the same time faintly reddish, showing an acid reaction. 

 If the organism be placed in a dilute methylene-blue solution 

 for a very short time, so that a few only of the physodes 

 — those situated peripherally — are coloured, and be then left 

 for some time in pure water, then the more energetic 

 streaming of the protoplasm which ensues causes the physodes, 

 stained and unstained, to become closely packed together, and 

 finally deposited in one or more vacuoles which lie near the 

 cell-wall. These would probably, like the oil-bodies, become 

 covered in time by a layer of cellulose. The arrangement in 

 rows of the physodes is probably due to frequent division, and 

 is seen best after the organism has been kept a short time only 



