Box— Vol. II.] HUS— CASSIA TOMENTOSA L. 331 



Distilled water 

 36. }4, per cent, iodine 



i^ per cent, potassium iodide 

 Distilled water 

 Distilled water 



I cannot here enter upon an extensive discussion of the 

 effects of these fixing-fluids. It is sufficient to say that 

 material fixed for ten to twelve hours in Flemming's strong 

 mixture showed as a rule no shrinkage; while material 

 fixed in other solutions (especially in the very dilute ones) 

 or left longer than twelve hours in Flemming's strong mix- 

 ture, showed considerable shrinkage, with the exception 

 perhaps of that fixed with Tellyesniczky's fluid, which 

 gave fairly good results. 



In fixing, two rules were observed: one, always to fix in 

 the field, since only in material fixed in this manner were 

 some of the earlier stages found in any number; the 

 other, to keep the material submerged, for only then could 

 the necessary penetration of the fixing-fluid take place. 

 Frequently air-bubbles adhered to the anthers, especially if 

 the latter were not separated, causing them to float. To 

 prevent this a very simple device was used : a disc was cut 

 off the lower end of the cork of the neckless fixing-bottle 

 and attached to a glass rod passing through the cork; this 

 kept the material submerged, while a notch in the edge of 

 the disc allowed the escape of any air-bubbles. 



After fixing, the material was washed from six to eight 

 hours in running water; a longer stay in water apparently 

 injured the finer structure of the cytoplasm. 



At this stage the material was sorted and then dehydrated. 

 It appeared here that a prolonged stay in weak alcohol 

 produced shrinkage. After reaching 95 per cent, alcohol, 

 the material remained for periods of about twelve hours 

 each, in absolute alcohol, a mixture of equal parts of abso- 

 lute alcohol and bergamot oil, bergamot oil, a mixture of 

 equal parts of bergamot oil and 43° C paraffin, 43° C 

 paraffin and 54° C paraffin. It was then imbedded in 71° C 



