MUSEUM OF COMPARATIVE ZOOLOGY. 99 



mind the condition in young egg cells, where the nucleus attains a rel- 

 atively enormous size. This great size of the nucleus in young egg cells 

 is explained by Korschelt ('89, p. 92) as due to its participation in the 

 trophic activity of the cell : " Seiu grosster Umfang fallt in die Zeit des 

 energischen Wachsthums der Eizelle." So in the gemmiparous regions 

 the large size of the nuclei must be considered as connected with the 

 growth of the cells. 



But if the growth of the cells is accompanied by a rapid ingestion of 

 food material (which the larger nucleus implies), some evidence of that 

 fact should be observed in the cells themselves in the presence of food 

 granules. Such food material in rapidly growing ovarian egg cells lies 

 near the nucleus. Stuhlmann ('87, pp. 13, 14) describes such a condi- 

 tion in the ovary of Zoarces. " Neben dem Keimblaschen, jedoch ein 

 klein wenig von seiner Membrau entfernt, bilden sich an verschiedenen 

 Stellen jetzt eigentiimliche Verdichtungen des Protoplasmas, die sich 

 ein wenig starker mit SafFranin farben als das Zellplasma." Such a 

 thickening of the protoplasma is represented in the figures as minute 

 granules. Korschelt ('89, pp. 123-125) mentions several other such 

 instances. 



It has seemed to me possible to interpret the stainable granules lying 

 near to the nucleus in gemmiparous tissue as such food material,^ par- 

 ticularly since we know that food material does exist in the coelomic 

 epithelium lying next to the cells which are about to divide rapidly and 

 to give rise to the inner layer of the polypide. That food is being taken 

 in by the inner layer cells from the coelomic epithelium is indicated by 

 the fact that the nuclei of the former cells lie near the latter epithelium 

 (cf. Figs. 15, 17, 18, 28, 56, etc.) ; for, as Korschelt has shown, the nu- 

 cleus tends to move towards the centre of activity of the cell. That these 



^ Granules similar to these appear to exist in the protoplasm of all cells. It 

 is their extraordinary abundance in the gemmiparous tissue upon which I lay 

 stress. They have been variously interpreted by different authors. Biitschli ('88, 

 pp. 1469-1472) describes various kinds of stainable granules in Ciliata which are 

 food products, and the general character of which accords with that of the gran- 

 ules referred to above. "Excretion granules" of Ciliata do not stain, according 

 to tliis author, which is an indication that the bodies in gemmiparous tissue are not 

 such. I am particularly struck by tlie fact that the food products of Protozoa are 

 chiefly found in parasitic forms, — Gregarinidas and parasitic Ciliata. These take 

 up food in solution from their hosts exactly as the cells of the body wall of Br3-o- 

 zoa do from the body cavity. Altmann ('90) has recently interpreted similar 

 deeply staining granules in other cells, as " die Elementarorganismen." I can 

 see no reason, on Altmann's theory, for the peculiar distribution of the granules 

 that I have found. 



