98 BULLETIN OF THE 
region, the stolon, gives rise to eggs. The same condition seems to exist 
in other Tunicates. 
III. On some Characteristics of Gemmiparous Tissue. 
In the preceding part of this paper the words “embryonic tissue,” 
“undifferentiated tissue,” have often recurred, and they are terms in 
wide usage in modern zodlogy. I do not know of any attempt to define 
further the real character of this tissue, nor to give its more detailed 
characteristics, other than that usually employed in the term plasma- 
reich, or “rich in plasma.” The persistence of yolk granules is, as 
Nussbaum (’80, pp. 2-14) and Goette (75, pp. 31, 32, 831) have shown 
in the case of amphibian embryos, indicative of the embryonic condition 
of cells, when these have been derived from an egg filled with yolk. 
It is very far from my purpose to go into a detailed discussion of the 
significance of embryonic tissue, for which I am not yet fitted ; neverthe- 
less, I wish to call attention to the minuter characters of gemmiparous 
tissue as I have found it in Phylactolemata and Paludicella. I have 
described it in some detail in preceding pages. 
First, then, gemmiparous tissue seems to stain more deeply than non- 
gemmiparous tissue in the same section. This character has been re- 
peatedly observed before by others, and Braem calls attention to it 
several times. T have already described how I found, by the use of 
high powers, that much of this depth of stain was due to the unusually 
large number of deeply staining granules scattered through the cell, but 
chiefly gathered about the nucleus (Figs. 6, 17, 18, ete.). So marked 
is the greater depth of the stain around-the nuclei, that, with a power so 
low that the nuclei are hardly distinguishable, their position is indicated 
by a deeply staining band. 
Secondly, gemmiparous tissue, as I have found it in the cases referred 
to, is distinguished by the possession of large cells, nuclei, and nucleoli, 
I had already noticed this fact in my studies on budding in Cristatella, 
and [ find that Braem has figured the nuclei in the budding region as 
larger than the average (cf. Braem, ’90, Taf. VII. Figs. 86, 88-90). 
My own figures show this repeatedly (Plate I. Figs. 3, 4, 5, 6, Plate II. 
Figs. 15, 17, Plate XI. Fig. 99, ete.). I have also noticed this to a 
certain extent in the marine Bryozoa, but, since the cells of the latter 
are smaller, and as I did not succeed in obtaining from them sections so 
satisfactorily stained, the results are not so reliable. In attempting to 
obtain an explanation of this phenomenon one involuntarily recalls to 
