MITOCHONDRIA IN TISSUE CULTURES 375 



the size of the mitochondrial thread or rod before the heat began 

 to act. When the heat is appHed the roitochondria do not divide 

 into a number of granules, as is sometimes the case when Janus 

 green is used, but each one rounds up as a whole and forms one 

 round granule for each mitochondrium. With rapid cooling of 



" ■ Vu. 



6.00P.M.0°C^-^ 6.00+PM46-C 6.01P.M4rc. 6.0,+ P.M. 48' C. ^ 6.02 PM. 47'C. 



^°^'''^'"'<^ 6.q3PM47"C 604Pm'46«C 6.05PM. 46''C 606PM, 45'C. 



6 07 P M 4S°r 



6.08 P.M 45°C 6.09 PM 45° C 6.10 PM. 46°C. 6.11 PM 46°C 



-^^ !<^' It % fe 



('^'PMA6°C 6-1?PM46°C 6.13 PM 46°C 613i^P_J,1. 47°c; ■6.14'p.M. 46°C. 



5# Cold water pas5ed "S^ ""^ ' "' ^ '"le'aled 



^•^k Ihroueh Ihe copIs * .^^ towards Ihe central 



ol the warm staffe / '""'>'■ ^ "' * '°'- 



6I5PM 46" C o"he warrr, stage 



6 18 P M 39° C 6 20 PM. 44° C '"""' "' ^ '^ '''* 



Cold water passed 



throueh the coils 



630 PM 46°C 632 PM 45°C 6.35 P.M. 4S°C 6.37 P.M. 45° C. 



6.45 PM 39° C 647PM 45°C. :'00 P.M. 48''C. 



Fig. 20 Part of living cell, drawn with camera lucida, showing position'of 

 4 mitochondria which were drawn at intervals, while the temperature was first 

 increased and kept at 46 to 48°C. for 15 minutes, then cooled to 39° for 3 minutes 

 and again increased to 44 to 46° for 20 minutes; again cooled to 39° for 8 min- 

 utes, and finally increased to 48° again. 



the preparation, by passing cold water through the coils of the 

 warm stage, the mitochondria return to their normal shape. 

 Prolonged heat, such as 46°C. for over an hour, has in a few 

 instances reduced the number and also the size of the mito- 

 chondria in a given cell. 



