Germ Cells of Leptinotarsa Signaticollis. 157 



cytoplasm than before. If the nuclear wall remains intact, the 

 egg does not become opaque even in the presence of oxygen. 

 According to Mathews the sperm brings into the egg cytoplasm, 

 which already contains an oxydase, two substances: a reducing 

 agent, the centriole, which counteracts the action of the oxydase 

 of the cell cytoplasm, and a very active nucleus which growls 

 rapidly and forms more reducing substance, and possibly some 

 oxydase. ' ' By the entrance of the sperm there is set up that extra- 

 ordinary series of opposite actions of oxydations and reductions 

 which accounts for the sudden bursts of respiratory activity which 

 probably underlies many of the most important syntheses and 

 chemical transformations in protoplasm" (p. 107). 



It has been shown by Fischer ('99) and others that the granules 

 in the living starfish egg take the basic stain and are therefore 

 electro-negative. It is also well known that a region of intense 

 reduction will act as a negative electrode, from which it follows 

 that granules staining with basic dyes are to be regarded as reduc- 

 ing substances. 



The conditions in the growing egg of L. signaticollis are of 

 course somewhat different from the material on. which the above 

 conclusions were based; but there are a number of very sugges- 

 tive points of resemblance that should be considered. 



In the first place, if one may judge at all from staining reactions, 

 the food stream coming from the egg string consist of particles 

 of a reduced substance which, through the activity of the oxydase in 

 the cytoplasm, is converted into an inert oxidation product, the 

 yolk. After fertilization every cleavage nucleus represents a 

 region of intense reduction which reacts with the oxydized yolk 

 converting it into living protoplasm. 



This hypothesis rests on the assumption that the staining reac- 

 tion of a substance is an indication of its chemical nature. A large 

 number of investigators (Ehrlich '91, Mathews '98 and others) 

 have demonstrated very clearly that staining with aniline dyes, 

 depends upon a chemical union between the dye and the substance 

 dyed. However, it often happens that in the process of fixation, 

 the chemical reaction of the tissue is made opposite from what it 

 was in the living condition, and this is especially true when the 



