106 
NOTES AND MEMORANDA. 
way of the proposed new grouping of the Ccelentera nemato^ 
pJiora is found in the Ctenophora. These have been re- 
cently shown by Haeckel to be most readily explained as a 
peculiar modification of the Hydromedusa3 ; at the same time 
there seems no reason to doubt that their genitalia develop 
from the endodermal cells of the ctenophoral canals. If 
this be so, the origin of the genitalia from this or that layer, 
would prove to be — in the Ccelentera at any rate — a matter 
of no genealogical import, instead of one of primary signi- 
ficance. 
An important character, serving to unite the Medusce acra^ 
spedcB with the Anthozoa, is found by the Hertwigs in the 
homology of the gastral filaments of the former with the 
mesenterial filaments of the latter. 
Muscular fibre (mesoderm) derived from Endoderm. — For 
some years the record of observed fact has pointed to the 
exclusive derivation of muscular and fibrous tissues in the 
Hydrozoa and Actinozoa from the ectoderm, the endoderm 
being employed solely as an epithelium lining the gastro- 
vascular system. Recently, however. Professor Claus, who 
has in recent years by varied and most valuable researches 
done so much towards placing our knowledge of the Hy- 
drozoa on a secure histological basi«, showed that Halis- 
temma possesses in its axis a delicate layer of ring muscula- 
ture derived from Endoderm (‘ Arbeiten aus d. Zool. Institut 
der Universitat,’ Wien, vol. i, 1878). This observation 
has been followed by the definite observation on the part of 
the Hertwigs (loc. cit.), to the efifect that in the Anthozoa 
(Actinia, Cerianthus, &c.) the musculature is chiefly derived 
from Endoderm, and only a small layer from Ectoderm. 
If this observation should prove to be thoroughly well 
founded, we have a new basis for the interpretation of the 
facts now known as to the origin of muscular and connec- 
tive tissues in the higher animals, the Coelomata or Tri- 
ploblastica. 
Recent Researches on Bacteria. — In a resume which 
we recently gave (this Journal, vol. xviii, p. 455) of the 
recent contributions to our knowledge of this most important 
poup of organisms we omitted to make any mention of the 
important researches of Dr. Alb. Fitz, of the Chemical 
Institute in the University of Strasburg. These have been 
published from time to time in the ^ Berichte der Deutschen 
Cbemische Gesellschaft zu Berlin ’ from 1876 up to the 
present time. Dr. Fitz has investigated from the chemical 
