aoe NOTES AND COMMENTS. 333 
their eggs, a work which, as in our Sticklebacks, devolves on the 
male parent alone. Although the fact of Gobies making nests has 
been known since the time of Rondelet (1554), no sufficiently-detailed 
account of the breeding habits of any species of the genus had yet 
appeared. The male Gobius minutus, for the nest, in tidal pools chooses 
usually the shell of some bivalve, frequently the Cockle, under the con- 
cave surface of which the sand is hollowed out and cemented by a 
special mucilaginous secretion from the skin of the fish ; a cylindrical 
tunnel gives access to the nest, which is covered over with loose sand. 
The female having deposited her eggs, fixed to the shell, the male 
watches over them, and courageously defends his nest during the 
whole period of incubation, lasting from six to nine days. 
Tue OLIGopyNAMics oF LivinG CELLS. 
A posTHUMOUS paper of Carl von Nageli has just been published 
at Zurich, with the mysterious title ‘‘ Ueber oligodynamische 
Erscheinungen in lebenden Zellen.”’ 
Towards the end of the discussion, we read that living cells may 
succumb to three different forces. Of these the Physical and Chemical 
are by far the most frequent and fatal; a third, of comparatively rare 
occurrence, he chooses to term ‘ Oligodynamic.” The paper is 
occupied by an examination of this peculiar power. 
The first startling announcement runs ‘“ fatal effect of nominally 
pure water on living cells.”” Ndageli was led to the conclusion that 
water possessed this property while testing the reduction of silver 
salts by living protoplasm. Solutions of the silver salts were made in 
the ‘nominally ” pure water, either distilled or spring water, and the 
cells experimented on were those of Spirogyra. 
In strong solutions, he noticed that the effect was chemical, the 
plants dying from poison; the cells lost their turgidity, the proto- 
plasmic layer separated from the wall, and the chlorophyll bands 
changed colour. 
With a solution so diluted that the merest infinitesimal trace of 
the salt only was present, the result was again death, but after a 
wholly different fashion ; the protoplasmic layer still adhered to the 
wall, and the cells retained their turgidity, while the chlorophyll 
bands shrunk together into a round ball. The effect was sometimes 
very rapid, and in four or five minutes the cell was killed. This, then, 
is the oligodynamic phenomenon, and, as he discovered at the end of 
a long research, was caused by molecules of copper present in the 
water. 
The “ nominally” pure water was brought through leaden pipes 
ending ina brass tap. Ifthe water was allowed to flow some time 
before being drawn for use, it was neutral; the experimenter could 
thus at will command oligodynamic or neutral water. In the case of 
