xxxvi INTRODUCTION. 



process also removes much of the offensive smell of freshly 

 macerated bones. Both these effects may, however, be more 

 quickly produced by steeping the bones in a clear solution of 

 bleaching powder, and afterwards washing them in running 

 water. 



Boiling the bones and then picking off the flesh yields 

 skeletons serving all the purposes of the student, though not 

 so white as those obtained by maceration. 



The preparation of cartilaginous skeletons is described at 

 p. 223. 



XIII. ON OBTAINING AMCEBM FROM SOIL. 



Ten grammes of chopped hay are put into a large flask 

 or beaker with one litre of distilled water and steamed for 

 three quarters of an hour. Then filter, make the filtered 

 liquid just alkaline to litmus by adding a few drops of sodium 

 hydrate and sterilise the alkaline liquid in an autoclave. 

 When cold, pour a small quantity into three or four Petri 

 dishes and inoculate each dish with a trace (not more than 

 half a gramme) of soil, almost any kind of garden or field soil 

 will answer. Put the dishes into a cool incubator or on the 

 laboratory table for a day or two, and then examine with a 

 microscope for amoebae. The amcebse vary in size from 

 very small forms to others measuring *03-*04: millimetres 

 in length when extended. They may be found in the en- 

 cysted condition and in all stages of activity. Subcultures 

 with fresh hay-infusion may also be made. 



For detailed examination, clean cover-glasses may be 

 dropped on to the surface of the culture medium and then 

 removed to slides, or a platinum loopful of the surface layer 

 may be put on to a slide and covered. 



