1 893. 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 Gobiiis minutits, 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. 



The Oligodynamics 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." Nageli 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 w^all, 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 

 ver}'^ 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 in a brass tap. If the 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 



