156 MADRAS FISHERIES BULLETIN VOL. XI, 



young fish placed in deep winter ponds for hibernation ; in the 

 following spring they are placed in large ponds where they mature 

 till fit for market. 



In one pond an experiment was being conducted in the method 

 of leaving the fry and the parent fish in the same pond throughout 

 the season, natural vegetation being encouraged for the protection 

 of the fry. While, on the one hand, the parents probably eat a 

 certain proportion of the fry, on the other hand they destroy a vast 

 number of noxious insects, beetles, etc., which kill an immense 

 number of the fry ; moreover the expense of transferring the fry is 

 saved. It is a question of comparative advantages. Apparently the 

 one advantage that this particular experiment has over the ordinary 

 Bavarian method is that only a given number of spawners, and 

 consequently a given quantity of fry, are allowed to a given area. 



The results both in gross outturn and net profits are consider- 

 able ; the balance sheets including all charges, cost of manure, etc., 

 etc., show a very useful net profit, which is surprising when the 

 waste and wretched nature of the land is considered. 



The giving of artificial food has been mentioned and it is obvious 

 that since the success of the Dubisch system depends mainly on its 

 proportioning the fish under cultivation to the amount of food 

 naturally available, it is possible by supplying extraneous food 

 to increase the weight of fish grown per acre and per annum, 

 especially as carp respond readily and rapidly to high feeding. 



Dr. Hofer of Munich has shown by actual experiment that it is 

 possible so to feed carp that specimens weighing lYz lb. in spring 

 weighed 5 lb. by the end of July, while Prof. Zuntz of Berlin 

 found that a three-year old carp can be made to triple its weight 

 during one summer. In the hotter parts of America such as 

 California, Mexico, Texas, etc., where the water is warm and full of 

 fish food, carp have attained the weight of 15 lb. in 3 years and 

 have increased at the rate of I lb. per month. In China a weight of 

 30 lb. in 5 years is obtained by supplying abundant food, and in 

 Japan it is common to sell large carp in their second summer, while 

 carp hatched in April grow to 10 inches in length by October when 

 placed in the rich paddy fields in June. The growths obtained by 

 Messrs. Hofer and Zuntz are abnormal being in non-tropical 

 climates and of fish not ordinarily growing to large size; the vora- 

 city and excellent digestion of the carp were taken advantage of to 

 stuff them, and they were as unhealthy as Strasbourg geese and 

 died, or would have died, of liver and fatty heart. In tropical 



