72 Thirty-Second Annual Meeting 



their influence on the growtli of trout has been noted, and there 

 have been s^ome instances in America of fish-culturists availing 

 themselves of their help in growing trout. In the transactions 

 of this Society for 1892 there were some interesting statements 

 from the personal experience of Mr. Fairbanks of Illinois on the 

 growing of trout in ponds in which they were sustained solely b\' 

 the natural food which grew there spontaneously, consisting 

 mainly of freshwater shrimps ; and the same matter has been dis- 

 cussed in some of the later transactions. I am not aware, how- 

 ever, that any attempt has been made to forward the multiplica- 

 tion of slirimps by any artificial hel]) further than transplanting 

 them from one water to another. 



The Crustacea which have received most attention are those 

 belonging to the family of entomostraca called daphnids. Daph- 

 uids thrive in water containing much vegetable matter in a state 

 of decay. Xot that they feed directly on such material, but on 

 the still smaller creatures that the decaying matter directly nour- 

 ishes. Decaying animal substances would seem to work in much 

 tbe same way, the multiplication of some of the entomostraca 

 being eventually much favored thereby. 



Fish cidturists have always been scheming to utilize these 

 arpiatic food resources, but generally with unsatisfactory results. 

 One of tbe most ambitious of these schemes was that of Tvugrin 

 and Dii Iiovcray at Gremat, in eastern France, which was 

 brought to American attention in 1S88 by the American consul 

 at .Marseilles. His rejjort and translation of a French report on 

 the sul)ject were pul)lished in tbe transactions of this society for 

 1S!)2. As the consul depicted it, Lugrin's method was very sim- 

 ])le and cheap and its results were marvellous. 1 quote his lan- 

 guage : "The i)rocess of Mr. I.ugrin. which has been patented 

 in several countries, consists in spreading \ipon the Ijottom of 

 these tanks a material impregnated with the elements necessary 

 to produce s})ontaneously a limitless number of Daphnia, Cy- 

 clops, Limnaea, as well as fresh-water shrimps, and the larvae 

 of varifuis P]phemera which form the natural aliment of trout 

 and oilier Salmoiiidae at all stages of their growth. Once con- 

 structed, and impregnated with this producing material — which 

 is of trifling cost, (This reproducing material, it appears from 

 the Fnited States letters patent granted to the inventors, con- 



