428 
r, A. POTTS. 
of the tissues and org’ans l>ave to be differentiated from the 
proliferated epiblast and mesoblast, the two most important 
systems, tlie nervous and muscular, are at firs'" formed as direct 
Text-fig. 3. 
s. g. 
Median longitudinal section through posterior end of budding stock 
(T. geminipara, VIII), showing Ijranching of nervous system 
represented l>y thick black lines, gen. a. Genital appendage of 
stock, pr. I. Proliferating lip of cushion. .st‘. Youngest stolon. 
stK Stolon with mesoblast just beginning to segment. sP. Stolon 
with median region segmented cut in horizontal section, st*. Stolon 
with ditfeientiated gonads. tr. m. Transverse muscle-bands in 
cushion, s. Aciculum. g. Gonad. X 70. 
continuations of the original systems of the stock. It is at this 
stage of development that they are first seen in the stolon. 
