VI. NOTES FROM THE BENGAL FISHERIES 

 LABORATORY, INDIAN MUSEUM. 



No. I. 



By T. Southwell, A.R.C.S. {Lond.), F.L.S., F.Z.S., 

 Deputy Director of Fisheries, Bengal. 



(Plates vii — x.) 



INTRODUCTION. 



Dr. Linton in presenting his report on the Parasites of fishes 

 of Beaufort, North Carolina, to the American Bureau of Fisheries 

 (i) ^ made the following remarks : — 



«' To the naturalist no defence need be made for the time and energy spen t 

 in the study of life in any of its phenomena. To those who are not naturalists, 

 however, some justification is due. Particularly does this become proper when 

 the general public, by means of such laboratories as those of the Bureau of 

 Fisheries, furnishes facilities for scientific enquiry. One who has never under- 

 taken to get knowledge at first-hand from nature is likely to have little conception 

 of the vast amount of work which is oftentimes necessary for the establishment 

 of a very simple proposition. Suppose, for example, exact and complete 

 information is desired as to the food of the English sparrow. It should not 

 require much reflection to convince anyone that before an adequate answer can 

 be made to such an inquiry, trustworthy observations must be made, by com- 

 petent investigators, on the feeding habits of this bird, both adult and young, 

 in different localities throughout the year, and through a series of years. But 

 the general public may wish to know, and in this case has a right to know, 

 what advantage there is to it in such scientific inquiry as is implied by an 

 investigation made on the food and the parasites of fishes. 



" It may, I think, be confessed that so far as may be seen while the investiga- 

 tions are in progress, much of the information which is collected will be of interest 

 only to zoologists. In view, however, of the well-known fact that many diseased 

 conditions, and even epidemics, result from the presence of parasites, and, 

 further, that the parasites are as a rule introduced, either as eggs or larvae, 

 along with the food, it is not difficult to see that the more complete and system- 

 atic our knowledge becomes of the interrelations of the animals which harbour the 

 parasite, interrelations which depend very intimately on the food habits of fishes, 

 the more certain are we to be able to cope successfully with any disease which may 

 arise. A case in point is furnished by one of the recent triumphs of medical 

 knowledge. It is scarcely possible that the cause of malaria and of yellow fever 

 could have been discovered if it had not been for the previous contributions to 

 knowledge made by investigators in parasitism. The germ of malaria is a 

 parasite whose round of life is passed in the blood-cells of man, and in certain 

 organs of the mosquito. The germ of yellow fever seems to have a similar 

 history. These interrelations between the mosquito and man were not even 

 dreamed of a generation ago. The history of trichinosis is now so well known 

 that a simple allusion to it in this connection is sufl&cient. Every well-informed 



Tliese numbers refer to the literature cited at the end. 



