118 THE MITOCHONDRIAL CONSTITUENTS OF PROTOPLASM. 



the mitochondria and the small lipoid vacuoles, but he could not discover any 

 relation whatever between these and the large vesicles which invade the whole 

 cell; so that he is unable to agree with Grynfeltt and Euziere concerning the 

 origin of the cerebrospinal fluid. 



Ciaccio and Scaglione (1913, p. 167) question the evidence in favor of this 

 interpretation. They call attention to the fact that Grynfeltt and Euziere used 

 for the most part the choroid plexuses of horses killed in the abattoir. They say 

 that horses of this kind are usually old and in poor condition and that for this 

 reason results based upon them are unreliable. 



Grynfeltt and Euziere (1913fl, p. 198) have not met Policard's criticism, but 

 they have answered that of Ciaccio and Scaglione by a careful study of animals of 

 different kinds killed in a variety of ways. They found that cells of these three 

 varieties occur in many forms of mammals, and they also discovered that bleeding 

 and the administration of pilocarpin increases greatly the number of cells contain- 

 ing the large, clear vesicles. They advance this as evidence that the vesicles con- 

 stitute in truth a stage in the formation of the cerebrospinal fluid. They have also 

 (19136, p. 101) extended their studies to the selachian Scyllium canicula among 

 the lower vertebrates. The choroid plexus cells in this animal have a particularly 

 well-developed striated border, which enabled them to make a detailed study of 

 the fate of the large clear vesicles. They observed them pass through the plasma 

 membrane and break for a moment the regularity of the striated border before 

 discharging into the ventricular cavity. This, they urge, is strong evidence in 

 support of the vesicular theory of the secretion of the cerebrospinal fluid and of 

 their general contention of the role played by mitochondria in its formation. They 

 do not, however, throw any further light upon the crucial question of the existence 

 of transitions between the mitochondria and the vesicles. In a still more recent 

 paper they make a general review of the whole problem, but contribute nothing 

 new to the discussion. 



My own studies lead me to agree with Policard, that Grynfeltt and Euziere 

 may be dealing with more than one process and that we have no suflftcient reason 

 to believe that transitions occur between the mitochondria and the vesicles. Even 

 should such transitions occur, we would want to know definitely whether or not 

 the vesicles do form the cerebrospinal fluid. 



.SECRETION OF THE PAROTID AND SUBMAXILLARY GLANDS. 



Regaud and Mawas (19096, p. 220) have studied the mitochondria in the 

 sero-zymogenic cells of the parotid of the ass and the human submaxillary. They 

 found that there is a quaUtative relationship between the amount of mitochondrial 

 substance and of zymogen; where there is a large amount of mitochondrial sub- 

 stance there is little zymogen, and vice versa. Between these two extremes there 

 is a complete series of gradations, and they believe these represent stages in 

 secretion. They describe transitions between the mitochondria and the zymogen 

 granules in the form of sphericMl Ixxlies of variable size and staining reaction 

 embedded in the suljstance of the mitochondrial filaments, and they formulate 



