5126 Fishes. 



a character of G. pungitius, are entirely wanting. The colour is very uniform as 

 compared with that of our ordinary sticklebacks: it is a somewhat metallic yellow- 

 green on the back, gradually becoming paler and almost white on the belly, the whole 

 being irrorated with minute black dots: the fins are very pale, almost colourless. The 

 male resembles the female until the month of March, when he begins to assume his 

 nuptial livery ; the median line of the breast and belly then becomes black, a colour 

 which day by day extends on either side, until all the lower parts of the fish becomes 

 of the most intense velvety black ; this eventually extends almost over the whole body, 

 the back only retaining slight indications of the normal colouring. 



Habits. — A fearless and ferocious little fish, instantly reconciled to captivity, and 

 attacking with fury any prior inhabitant of the vessel in which it is placed : it will 

 frequently seize a fellow-prisoner by the gill, the tail or a fin, and retain its grip with 

 the firmness of a bull-dog: in tlie same way it will instantly seize a worm when 

 presented to it, and allow itself to be drawn out of the water without relinquishing its 

 hold: the females become very much distended with ova, and deposit them simul- 

 taneously ; they are very large, generally eight or ten in number, and are immediately 

 devoured, if found by fishes of the same or other species: its nest is not known to me. 

 Unlike other species of Gasterosteus, it will not exist when confined in salt water, 

 however diluted. 



Habitats. — It is the most abundant of all fishes in the marsh ditches on the Surrey 

 side of London ; but it is rarely met with in ponds : in the ditches by the side of the 

 Surrey Canal it breeds by myriads, and is a source of endless amusement to the boys 

 of the neighbourhood, a stick, a thread and a worm being the only requisites for its 

 capture. 



In conclusion, I need scarcely say how much I shall feel obliged for additional 

 information on this subject. The sticklebacks are generally considered too common 

 to be worthy of notice, and I believe, for this very reason, we have more to learn 

 respecting the distinction of species and the details of their interesting economy than 

 of any other genus of fishes. — Edward Newman. 



Some Observations on the Disease in Fish called Fungus, which is 

 so fatal in Aquaria. Fish Ponds, fyc. By Dr. Frazer.* 



The plant which is the subject of the present communication is by 

 no means of extreme rarity, nor is it of local or limited occurrence. 

 It has been observed with considerable accuracy, and always with 

 interest, by many scientific naturalists, and we possess several good 

 descriptions and drawings of it, both in the form of detached essays 

 and in systematic treatises : thus, amongst others, Ledermuller, Wors- 

 berg, Spallanzani, Lyngbye, Kutzing, Cams, N. V. Esenbeck, Agardh, 

 Berkeley, Bratin, and especially Unger, have each contributed to our 

 knowledge of its natural history, and recorded its most striking pecu- 

 liarities ; and as a proof of its extensive geographical distribution, I 

 * Read at the Dublin Nalm#l History Society, on the llth of April, l^oO. 



