(442) 
distinguished, many of which may be illustrated by a great number 
of special examples and which all amount to this: that an atom 
or a group linked to N or O shows an inclination to pass from this 
atom to the nucleus and then always (or nearly so) changes place 
with the H atoms occupying para- and ortho-places. Whether the 
meta-places are occupied or not does not affect this isomerisation 
process. 
If we now limit ourselves to nitric acid it may be observed that 
the idea that in the,nitration of aniline derivatives (best in the case 
of those containing NHX instead of NH,) the nitro-group should always 
combine first with the nitrogen forming nitramines, befure passing 
on to the nucleus, has already been suggested by BAMBERGER and 
confirmed by experiment. After Dr. BLANKSMA’s experiments we 
arrive at a similar conclusion as regards the formation of nitrated 
phenols. This is confirmed by another observation of Dr. BLANKSMA 
that if the phenol-hydrogen of symmetric dinitrophenol is replaced 
by methyl, the ready bromination or nitration is no longer possible. 
Efforts will be made to prepare the as yet unknown nitrates of the 
phenols and, if successfui, their behaviour will be closely studied. 
Physiology. — “On the development of the entoderm, of KUPFFER’s 
vesicle, cf the mesoderm of the head and of the infundibulum 
in Muraenoids” (preliminary paper), by Dr. J. Boerke. (Com- 
municated by Prof. T. PLACE). 
(Communicated in the meeting of January 25, 1902). 
In his well-known paper on pelagic eggs of the Gulf of Naples, 
RAFFAELE described five species of big pelagic eggs, which were found 
in the plankton of the Gulf during the months of August and Sep- 
tember, which he suggested that might belong to different members 
of the Muraenoid group. 
In 1893 and 1896 Grassi and CALANDRUCCIO confirmed this theory, 
but they did not study the eggs closer. 
During the summer of 1900 and 1901 I had the good fortune to 
secure several hundreds of these eggs during a stay at the Stazione 
Zoologica at Naples, and was enabled to study all the stages of 
development of the embryos untii the critical period. The description 
and suggestion of RAFFAELE I found to be perfectly true, and moreover 
I collected three other species of eggs, which although undoubtedly 
belonging to Muraenoïd species, could be distinguished sharply from 
the other five spp., described by RAFFAELE. From these they differed 
in the dimensions of the yolksphere and the perivitelline space, in 
