40 BACTERIAL POISONS. 



of zoologists. MOBIUS states that the peculiarities of the 

 supposed poisonous variety pointed out by VIRCHOW and 

 SCHMIDTMANN are really due to the conditions under which 

 tie animal lives, the amount of salt in the water, the tem- 

 perature of the water, whether it is moving or still water, 

 the nature of the bottom, etc. Finally, MOBIUS states that 

 the sexual glands, which form the greater part of the 

 mantle, are white in the male aud yellow in the female. 

 However, it has been shown later by SCHMIDTMANN and 

 VIRCHOW that edible mussels may become poisonous if left 

 in filthy water for fourteen days or longer, and, on the 

 other hand, poisonous ones may become fit for food if kept 

 for four weeks in good water. 



Cats and dogs which have eaten voluntarily of poisonous 

 mussels have suffered from symptoms similar to those ob- 

 served in man ; and rabbits have been poisoned by the 

 administration of the water in which the food has been 

 cooked. A rabbit which was treated in this manner by 

 SCHMIDTMANN died within one minute. From these 

 mussels BRIEGER extracted the ptomaine mytilotoxine, 

 which will be discussed in a subsequent chapter. This 

 poison has a curare-like action. Whether or not those 

 mussels which produce other symptoms also contain pto- 

 maines, remains for future investigations to determine. 



In 1887 three other cases of mussel poisoning, one fatal 

 case, occurred at Wilhelmshaven, the place which supplied 

 BRIEGER with the mussels from which he obtained mytilo- 

 toxine. SCHMIDTMANN has found that non-poisouons 

 mussels placed in the waters of this bay soon become poi- 

 sonous, and that the poisonous mussels from the bay placed 

 in the open sea soon lose their poisonous properties. LIN- 

 DER has found in the water of the bay and in the mussels 

 living in it a great variety of protozoa, amoeba, bacteria, 

 and other lower organisms, which are not found in the 

 water of the open sea nor in the non-poisonous mussel. He 

 has also found that, if the water of the bay be filtered, non- 

 poisonous mussels in it do not become poisonous. He 

 therefore concludes that poisonous mussels are those which 

 are suffering from disease due to residence in filthy water. 



