844 GENERAL METABOLISM [pt. m 



Thus the differences between the kinds of echinoderms were almost 

 imperceptible, and the eggs of a polychaete worm and a tunicate 

 agreed very well with them. All the figures were at least one pYL 

 unit higher than those obtained by the method of microcompression. 

 We attributed this simply to the slighter degree of injury done to 

 the cell by the micro-injection method. At about the same time 

 Schmidttman, using a technique in which she introduced solid 

 particles of indicator into the cells, reported a value of j&H 7-6 to 7-8 

 for the mammalian egg-cell, taken from ovaries of rats, mice, rabbits, 

 and cats. 



This led to an extended controversy, the details of which cannot 

 be given here, but may be found in the original memoirs. Vies and 

 his associates maintained that our readings had been insufficiently 

 corrected, we maintained that tht pH. of the egg-cells studied was in 

 the neighbourhood of 6-5, and that on cytolysis values identical with 

 those obtained by him were found. We regarded cytolysis as an acid- 

 producing process, and considered that his technique was not capable 

 of dem.onstrating the pH of an uncytolysed cell. Thus on injecting 

 bromcresol purple into an unfertilised Strongylocentrotus egg-cell, for 

 instance, one sees what we called a "purple puff" which lasts for 

 some seconds, then giving way to a greenish tint, which soon turns 

 yellow. But on microcompression of such an egg, according to Vies, 

 the first colour seen in the cell is yellow or yellowish green, so that, 

 in our opinion. Vies was never observing uncytolysed eggs at all. 



In support of our view that the intracellular reaction is near the 

 neutral point, and that cytolysis liberates acid substances which 

 interfered with Vies' method, there are many observations. Since, 

 as we have seen, Warburg has shown that the lactic-acid-producing 

 mechanism is not peculiar to muscle, but exists in all tissues, the 

 probability of lactic acid being produced in cytolysing eggs is very 

 considerable. Again, any vacuoles would naturally be expected to 

 burst when the cell is squashed, and, since Greenwood showed as 

 long ago as 1894 that the food-vacuoles of protozoa are distinctly 

 acid, there is obvious danger from that source. Recently Rowland 

 has found a pYi of 4-3 in the digestive vacuoles of Actinosphaerium. 

 But, further, the researches of Parat and his school have shown 

 that the so-called Golgi apparatus is in all probability a series 

 of intraprotoplasmic spaces, a vacuome, which contains an acid 

 liquid, and is filled up by the metallic reagents usually employed 



