G. GENERAL NATURAL HISTORY AND ZOOLOGY. 307 



extent in the case of animals, especially in fishes, particularly 

 where transported to countries in which that particular group 

 was originally wanting. 



Wonderful tales are told of the rapidity of growth of the 

 German carp in California, to the effect that they will be- 

 come as large in one year as they do in Germany in three or 

 four, and be capable of reproduction in the same period. 

 However this may be, we are assured that the success which 

 has attended the introduction of the Eno-Hsh trout into Aus- 

 tralia has been quite remarkable. A recent writer states 

 that in November, 1872, about 400 fry were turned out at 

 Ballarat, having been hatched in the month of September 

 previous. In January, 1 875, or twenty-six months after being 

 liberated and twenty-nine months after hatching, some of 

 these fish were taken in a net, one of them, a female, weighing 

 an ounce less than 10 pounds; two others turned the scales 

 at 9| pounds, two at 9 pounds, and four or five others aver- 

 aged 7-J pounds each ; and the smallest fish taken weighed 

 over 6 pounds, and all were in splendid condition. 



A somewhat similar experience was had in the case of cer- 

 tain perch, the progenitors of which had been brought the 

 year before from England. Three years previous a soda- 

 water bottle, filled with eggs of perch, was placed in a la- 

 goon at some distance from Ballarat. The fish hatched out, 

 and quite lately several specimens weighing 5 pounds and 

 upward have been taken. 19 A, April 24, 405. 



INFLUENCE OF THE HOOTS OF LIVING VEGETABLES UPON 



PUTREFACTION. 



Jeaunel states that the project for utilizing the waters of 

 the sewers of Paris by allowing them to flow over 2000 hec- 

 tares of cultivated fields, near Paris, has caused some appre- 

 hensions on the part of sanitarians. In reply, one may in- 

 quire why the neighboring island of Jennevillius, receiving, 

 as it does, the enormous quantity of 240,000 cubic meters of 

 putrid water, should not be a dangerous centre of infection, 

 and menace the health of the populations of all the neighbor- 

 ing suburbs, and even of Paris, the northwest quarter of which 

 is only two kilometers distant from the irrigated lands. This 

 great question seems answered by experience. The inhabit- 

 ants of the villages above quoted, the laborers who live upon 



