164 bulletin: museum of comparative zoology. 



authors have claimed them to be. For instance, one slide stained by 

 this method showed the following distribution of red and green: in 

 young oocytes every part — cytoplasm, nucleus and nucleolus — green; 

 in larger oocytes, cytoplasm green, reticulum of nucleus brownish or 

 maroon, nucleolus blue; in cells of the polyp, nucleus and nucleolus 

 green, cytoplasm red; in the cells of embryos, chromosomes in a 

 mitotic figure green, spindle fibres and asters red, cytoplasm maroon. 

 Sometimes the cytoplasm and nucleus of an embryo cell were of 

 nearly identical colors, while in other cells of the same embryo they 

 were of different colors. Hence in some cases the red and green stains 

 would give the same results, in regard to chromatin and non-chromatin, 

 as those produced by other stains; while in other cases, the relation 

 of the red and green colors would lead to results different, and indeed 

 opposite, from those obtained by other stains. It is almost certain, 

 I think, that the green in these mixtures is not a specific chromatin 

 stain, but is modified in its action by several factors, probably physical 

 as well as chemical ones, as has been maintained by Heine ('95-6), 

 Mathews ('98), Fischer ('99), and Tellyesniczky (:05J. 



III. Observations. 

 A. Pennaria tiarella. 



1 . Growing eggs. — In the present investigation no attempt has 

 been made to work out the oogenesis, except to a slight extent in the 

 matter of the relation of the chromatin to the nucleolus. Smallwood 

 ('99) and C. W. Hargitt (:00, :04'') have paid some attention to oogen- 

 esis and growth phenomena; what I have seen is, in the main, con- 

 firmatory of their results. In addition to the absorption of oocytes 

 by the growing egg, I may mention another possible method of nourish- 

 ment not considered by my predecessors. In the later stages of growth, 

 when nearly all the oocytes have been absorbed, the large eggs seemed 

 generally to have several short pseudopodia attached to the entoderm 

 of the manubrium. This suggests that during this period of growth 

 nourishment may be obtained directly by absorption from the manu- 

 brium, much as in the case of Eudendrium (C. W. Hargitt, :04^, 

 Congdon, :06) and Clava (Harm, :03, Hargitt, :06). 



In oocytes before the growth period the chromatin of the nucleus is 

 rather deeply stainable, and is arranged in masses near the periphery 

 of the nucleus. These chromatin masses occupy a delicate linin 



