BULLETIN OF THE 
10, RÔLE or THE MESODERMAL VACUOLATED CELLS, 
Allman (56, p. 36) observed that at the time a lateral branch was 
well formed, and before the origin of tbe polypide, the internal outline of 
the body wall was uneven, and he figures (Plate XI. Fig. 4) very large 
cells lying on the inside of the body wall. Korotneff (74, Taf. XI. 
Figs. 1-3, ’75, pp. 369, 370) progressed a step farther, and recognized 
a distinction between large, coarsely granular cells projecting into the 
cavity of the bud, especially near the tip, and the surrounding epithelial 
cells. Braem (90, p. 126), finally, has described them more accurately. 
He finds cells filled with numerous granules in the youngest branches of 
the colony. Immediately around the bud, such cells are less abundant ; 
probably, he says, because their granules have been absorbed in the 
process of formation of the polypide. He compares the granules with 
the yolk spherules of the statoblast cells, and believes that they are to 
be regarded as food matter. 
My observations and conc.usions, achieved independently of B 
raem’s, 
fully confirm his. I have succeeded, moreover, in obtaining some addi- 
tional evidence as to the function of these cells, a subject to which I 
have paid some attention. 
First as to the distribution of the cells, and their frequency in different 
regions. We can best get an approximate idea of this by counting the 
number of the reticulated cells in each section of a series which in- 
volves a young polypide and the regions immediately above and below 
it. It is not possible to do this with perfect accuracy, because there is 
no sharp line of distinction between reticulated and non-reticulated cells ; 
but I have made the count without prejudice, and I believe as fairly as 
possible. When the bud of the polypide has reached about the stage 
shown in Plate III. Figure 28, the number of reticulated cells seems to 
have nearly reached a maximum. In the series from which this figure 
was taken there was an average of 4.8 reticulated cells to the section in 
the ten sections distal of the bud. There was an average of 11.2 reticu- 
lated cells to the section for the twenty sections which passed through the 
bud, and 11.2 for the eleven sections proximal of the bud in the region 
perforated organs have been described by Smitt (’67, p. 426), Nitsche (71, pp. 
429-422), and Vigelius (’84, p. 26) for Flustra, by Freese (’88, p. 7, 18, 14) for 
Membranipora, by Ostroumoff (’864, p. 13) for Lepralia, by Claperede (’70, p. 160) 
for Bugula and Serupocellaria, by Ehlers (’76, p. 14) for Hypophorella, and by 
Joliet (77, p. 222) for Bowerbankia. Nitsche alone (’71, p. 455) has had anything 
to say upon their origin, and this apparently not the result of direct observation. 
