1 MUSEUM OF COMPARATIVE ZOOLOGY. 73 
Braem (’90, pp. 33 and 44), Ehlers (790, p. 9), and others, have since 
done. I shall represent the mass of indifferent cells by an asterisk, 
and individuals (according to Chun’s nomenclature) by the use of the 
large and small letters of the Roman alphabet, and, finally, by Greek 
letters. The typical stock of Paludicella might then be graphically 
represented thus (cf. Plate I. Figs. 2 and 2°) :— 
* 
* CO * 
x“ OR 
xabax 
* * * 
*b * KR xx 
* * *¥BaaaB* 
xaaak KEIN 
* * a * * * 
(1) 3 D 2) B A 
* xa% Ko 
* xaaax KK %* 
k*k * x Baaaßx 
xbx* Xk k% 
* X% 
xabax 
* Cx 
* 
Here the letters indicate polypides or their Anlagen, and the asterisks 
indifferent tissue. The individuals represented by capital letters may be 
called primary individuals; they may be said to belong to the primary 
series, and to have been derived from the primary indifferent mass. 
The individuals represented by small Roman letters will then be secon- 
dary individuals, belonging to the secondary series and arising from sec- 
ondary masses; etc. It is to be observed that this indifferent tissue is 
here found only at the tips of branches or Anlage of such. No asterisks 
are found adjacent to, the adult polypides A, B, C, etc., which have 
given rise to lateral branches, and these have therefore no power of pro- 
ducing new parts of the colony. The asterisks must not be regarded as 
having been descended from the letters which they adjoin, but from the 
terminal asterisks only; that is to say, in Paludicella embryonic tissue 
has originated from terminal embryonic tissue, and not from indifferent 
tissue left remaining alongside of the polypides. 
Jonditions differing in an interesting manner from these were found 
by Braem (’90, pp. 18-32) and myself (Davenport, '90, pp. 103-106) in 
Phylactoleemata. In Plumatella Braem has shown in the clearest man- 
ner how some of the embryonic tissue around a polypide at the proximal 
