THE MITOCHONDRIA AND OTHER STRUCTURES. IOI 



details of the cellular structure nor their behavior could be 

 carefully studied while the cells remained in the follicle as de- 

 scribed by Goldschmidt, but that for this purpose it is necessary 

 to observe isolated cells which lie close to the cover slip. 



Fixed Preparation. The mitochondria and other structures 

 present in various types of fixed material have been studied 

 more or less in detail by numerous observers, with results which 

 depend very largely upon the state of preservation of the material 

 studied. Duesberg, J. ('n) has reviewed this literature so it 

 is unnecessary to repeat it here. In an earlier paper Duesberg, J. 

 ('10) gives a clear and complete description of the behavior of 

 the mitochondria in Blatta germanica, which corresponds in all 

 but a few details with that given below for Chorthippus curtipennis. 



METHOD. 



The cultures were prepared in the usual manner (Lewis, M. R., 

 and Lewis, W. H., '15) and all precautions were observed in order 

 to keep them not only chemically clean but also aseptic, except 

 in cases where the period of observation was to extend over only 

 a short time, as for instance when a vital stain was used. 



Various different culture media were tried and the one which 

 appeared to be most nearly isotonic with the body fluid of the 

 grasshopper and which also was most favorable for growth was 

 practically Locke's solution i. e., NaCl 0.9 per cent., CaCU 0.025, 

 KC1 0.042 per cent., NaHCOs 0.02 per cent., dextrose 0.25 per 

 cent., peptone 0.2 per cent., but since the observations were made 

 at Woods Hole where running sea water is supplied, the same 

 concentration of salts was obtained by a dilution of the sea water 

 as follows: sea water 30 c.c.+distilled water 50 c.c. + bouillon 

 20 c.c.+dextrose 0.25 gram + NaHCOs 0.02 gram. The bouil- 

 lon was prepared in the same manner as that used for bac- 

 teriology, except in this case grasshopper muscle was used in 

 place of beef. A solution of peptone alone can be substituted 

 for the bouillon with rather good results. The culture medium, 

 which is successful, depends largely upon the amount of evapora- 

 tion which takes place in the technic of the individual observer. 

 This can be determined from the appearance of the preparation 

 itself, for it was found that when the medium was too concen- 



