THE OYSTER INDUSTRY OF NEW JERSEY. 489 



returned tliem. It was finally deemed advisable that an investigation 

 sliould be made with a view to ascertaining the cause and natiue ot 

 the viridit}^ and removing, so far as practicable, false impressions on 

 the i)art of consumers regarding it. Accordingly the services of Prof. 

 Julius Nelson, ph. d., biologist of the Agricultural College Experi- 

 ment Station at ISTew Brunswick, N. J., were secured by Messrs. 

 Horner and Austin, wholesale dealers and shippers of oysters and 

 »lams at Tuckerton. On October 6 Prof. Nelson made a personal 

 inspection of the grounds and an investigation of the oysters and 

 clams, the results of which were transmitted to Messrs. Horner and 

 Austin, October 18, and published in the Tuckerton Beacon of Novem- 

 ber 3, 1892. The essential parts of Prof. Nelson's report, as addressed 

 to Messrs. Horner and Austin, are subjoined: 



I have examined the clams you sent and have carefully looked over the grounds 

 at Tuckerton, and can report that the color is due to the presence of a species of 

 microscopically-small vegetable organism, which the dryness of the past summer has 

 allowed to multiply iu the waters on the beds and which the clams have eaten in 

 large quantities, so that their tissues have become stained by the color of their food. 

 The dye is perfectly harmless. Numerous t-ests and analyses made by several scien- 

 tists, both of this country and Europe, show that copper is not present; neither does 

 microscopical examination show any disease nor any parasites present. Oysters 

 aflfected in a similar way are in special demand in Europe, not for their color, but 

 because of their careful cultivation, the fine qualities being in no wise deteriorated 

 by the fact that their tissues are stained by their food. 



My investigation of the green clams and oysters of Tuckerton Bay brings out the 

 following facts: 



(1) The peculiar pea green is for the most part confined to the gills, but some 

 specimens have the so-called "liver" also changed from its natural brownish to a 

 brownish-green tint. 



(2) The water taken from the clam beds has a marked greenish color and deposits 

 a green sediment on standing. 



(3) This sediment consists of a nearly infinite number of very small vegetable 

 cells or microscopic plants known as algae, among which are many diatouis, but 

 especially a species of Botrycoccus. 



(4) The digestiA'e canal of the clams was found crowded with these low organisms 

 in process of digestion, but the color was not changed by the digestive juices. 



(5) After the clams are removed from the water the color fades somewhat day by 

 day, and would probably very soon disappear if they could be placed in water free 

 from these algic. 



(0) The "infection" began on the flats, in shoal water, amidst floating eelgrass, 

 which, owing to the dry and stormless summer, was little disturbed and therefore 

 presented the most favorable conditions for the development of this species of food. 



(7) The "infection" began in August and has now succeeded in gradually cover- 

 ing the entire bay. 



(8) The clams become colored within a very few days after the water iu which 

 they live has become impregnated by the algjc in question. 



(9) These clams are in as fully excellent condition of fatness and flavor after 

 "infection" as before, owing, doubtless, to the abundant food thus furnished them. 



(10) No^evil results have followed the free eating of them by persons having oven 

 very sensitive stomachs. 



(11) The color is naturally suggestive of "copper" or "Paris green " to ]uM)plo 

 ignorant of the true nature of the " infection/' but no trace of copper or other injuri- 

 ous substance has been found. 



