268 DK. J. B. GATENBY ON THE GERM-CELLS AND 



7. The Minute Cytology of the Gastral Epithelial or 

 Collar Cell of Grantia. 



Hirschler (8) was the first to show the presence of a typical Golgi 

 apparatus in the collar cell of a sponge (Spongilla). Unfortunately this able 

 observer did not push his work very far, and we do not know in Spongilla 

 in what way the Golgi apparatus is related to the centrosome or flagellum. 

 The technique indicated for work on the Golgi apparatus of sponges is that 

 of Kopsch (4) ; pieces of sponge are left for two weeks in 2 per cent. 0sO d 

 and then washed, dehydrated, and embedded in hard wax. The sections are 

 cut as thinly as possible and may be treated in turpentine to clear them 

 somewhat — five minutes is long enough for thin sections. In Grantia such 

 preparations show the Golgi apparatus in the collar-cells in the same position 

 as indicated by Hirschler for Spongilla. PI. 19. figs. 1. 2, 3, and 4 are drawn 

 from preparations of collar-cells, to show their minute structure. In PI. 19. 

 fig. 3 is a group of cells fixe:l in Hermann-without-acetic acid, mordanted 

 in K 2 Cr 3 7 and stained in either Iron Hsematoxylin or Altmann. The 

 granules contained in these cells are, I believe, the true mitochondria. 

 Hirschler (8) figures such fine mitochondrial granules in Spongilla, and I 

 think there can be no doubt as to the presence of mitochondria in the flagel- 

 lated cells of Grantia. 



In PI. 19. fig. 2 is drawn a Kopsch preparation of Grantia compressa to 

 show the Golgi apparatus ; as in Spongilla, it is a spherical or irregular 

 object lying on the periphery of the cell and staining dark brown or black 

 in osmic acid. In these cells the other cytoplasmic granules become light 

 brown. PI. 19. fig. 4 is a high-power drawing of a collar-cell treated by 

 Kopsch. The Golgi apparatus is "seen to be formed of a central archoplasmic 

 sphere (AS), surrounded by a rind of Golgi apparatus substance (GA) -; 

 this preparation was differentiated in turpentine, while the apparatus in 

 PI. 19. fig. 1 A & B was left untreated. 



In many cases, such as in PI. 19. fig. 1 A, it can be shown that the flagellum 

 passes into the apparatus, but in others, such as in PI. 19. fig. 1 B, the 

 centrosome is distinct from the archoplasm and lies on the nucleus. I think 

 that in most examples the centrosome lies inside the Golgi-cum-archoplasm 

 apparatus, and the filament issues from the latter. In PI. 19. fig. 4, below 

 the apparatus at C ?, lay a granule which is possibly the centrosome. Now 

 besides the mitochondria, which in some cases may be much finer than 

 depicted in PI. 19. fig. 3, there are other much larger granules marked Y in 

 PI. 19. figs. 1 and 4. These are difficult to distinguish from the mitochondria, 

 and they may stain black bj- prolonged immersion in Iron Haematoxylin ; 

 by staining in Altmann they are not tinged, and then can be distinguished 

 from the mitochondria. In Cajal's silver nitrate method the granules may 



