THE MICKOiMANIPULATION OK LIVING CELLS 



29 



physiological strueture ha\e Ix'cii vai'ioiisly 

 termed inieellae by Nii<ieli, i)lasoines by 

 Wiesiier, bioblasts by 0. Hertwiji', etc. An 

 atteniiit to give a chemical sigiiifieanee to 

 the ultimate unit of liviii<i- matter was made 

 by PHii-i-er (1875). Pfliiyer postulated a 

 livin<i' ])roteiii {lehendiges Eiweiss) mole- 

 cule with a constitution based on a cj^ano- 

 <ien radical. Its stability and lability were 

 sup]iosed to depend upon interehanji'es of 

 atom yroui)s in the molecule, imluced by 

 the consumption of oxygen and the libera- 

 tion of carbonic acid. 



Much earlier than Pfliiger is the almost 

 forgotten account of Fletcher of the Uni- 

 versity of Edinburgh in 1835. In his 

 "Rudiments of Physiology" Fletcher at- 

 tacked the old hypothesis of a vital spirit. 

 As an alternative he suggested that the 

 elements composing living matter are in 

 a peculiar state of combination. "That, in 

 fact, no albumen, fibrin, myosin, protagon, 

 or fats exist as such in the living matter, 

 but that the sum of the elements of all these 

 is united into a compound, for which we 

 have no chemical name, and of the complex 

 mode in which the atoms are combined we 

 can form no idea ; and it is only at the 

 moment of death that those chemical com- 

 pounds with which we are familiar, take 

 their origin. In fact, that death means 

 simply the resolution of this complex com- 

 bination into the simpler compounds, albu- 

 men, fibrin and the rest which w^e find on 

 analysis."* 



The newer developments in the extrac- 

 tion of proteins, e.g., by idtracentrifuging 

 at very low temperatures, have made pos- 

 sible the isolation of certain viruses hitherto 

 unobtainable by the usual chemical means. 

 May not this be a first step toward isolating 

 the extremely unstable complex which at 

 present can be termed only as protoplasmic 

 protein ? 



In regard to the morphology of proto- 

 plasm, mention should be made of the inti- 

 mate relation between the cytoplasm and 

 the investing plasma membrane. Thus far 

 it has been impossible to separate the two. 



4 Quoted from ' ' The Protoplasmic Theory of 

 Life ' ' by John Drysdale, London, 1874. 



The disintegration of the one has always 

 accompanied the disintegration of the 

 other. Can it be that the stability of the 

 protein complex of protoplasm depends 

 upon the presence of a plasma membrane 

 whose selective permeability preserves the 

 proper environment within the cell? A sea- 

 urchin egg torn open in a solution of po- 

 tassium chloride reacts very differently 

 from one torn in a solution of calcium 

 chloride (Chambers 1924). The exposed 

 cytoplasm disperses in potassium chloride 

 Avhile it coagulates in calcium chloride. A 

 medium which wdll keep the cytoplasm 

 from destruction must be between these 

 two opposite effects. The discovery of a 

 suitable medium having a proper mixture 

 of chemical substances and the right physi- 

 cal conditions of density, pH, etc., may 

 eventually be made. In such a medium the 

 disruption of the plasma membrane might 

 be induced so as to set free, nnaltered, the 

 protein complexes from the confines of the 

 microscopic cell. 



References Cited 



Chambers, E. and Sands, H. C. 192.3. A Dissec- 

 tion of the Chromosomes in the Pollen Mother 

 Cells of Tradescentia virginica L. J. Gen. 

 Physiol., 5: 815. 



CHAirBERS, E. 1924. Microdissection and Injec- 

 tion Studies on the Antagonistic Action of Salts 

 upon Protoplasm. Am. J. Physiol., 72: 210. 



Chambers, E. and Fell, PI. B. 1931. Micro- 

 operations on Cells in Tissue Cultures. Proc. 

 Boy. Soc. Lond., 109: 381. 



Chambers, E. and Kopac, M. J. 1937. The 

 Coalescence of Sea Urchin Eggs with Oil Drops. 

 Ann. Bept. Carnegie Inst. Wash. Yr. Bl\, 36: 88. 



. 1937. The Coalescence of Living Cells 



with Oil Drops. I. Arbacia Eggs Immersed in 

 Sea Water. J. Cellular Comp. Physiol, 9: 331. 



Chambers, E. 1938a. Cytoplasmic Inclusions and 

 Matrix of the Arbacia Egg. Biol. Bull., 75 : 350. 



. 1938b. The Physical State of Proto- 

 plasm with Special Reference to Its Surface. 

 Am. Naturalist, 72: 141. 



Cohen, B. and Chen, T. T. 1933. Reduction In- 

 tensity in Anaerobic Amoeba dubia. Proc. Soc. 

 Expti. Biol. Med., 31 : 115. 



COSTELLO, D. P. 1938. Behavior of Oil Drops in 

 the Centrifuged Egg of Nereis limbata. Anat. 

 Record, 72: 72. 



Dawson, J. A. and Belkin, M. 1929. The Diges- 

 tion of Oils by Amoeba proteus. Biol. Bull., 56: 

 80. 



