MALAC0PTERYG1I ABDOMINALES. 453 



arc subject to a malady which is often mortal ; their head and 

 back become covered with excrescences similar to moss. It 

 appears that this disease also occurs to the young carps 

 which live in snow-water or in water which is corrupted: 

 snow-water likewise produces pustulous germs under the 

 scales, which fishermen call the smallpox. Their intestines 

 also frequently contain worms, and their liver becomes ul- 

 cerated. 



The carps live habitually on the larvae of insects, or 

 worms, small testacea, grains, roots, and the young shoots of 

 plants. They are seen to devour the leaves of lettuce and of 

 other succulent and tender plants which are cast into the 

 water. Bloch assures us that the leaves and seeds of salad 

 particularly agree with them, and fatten them more quickly 

 than any other aliment. They are also observed to dart out 

 of the water to seize on the insects which hover over its 

 surface, or which fall into it, such as the achetes, and some 

 species of bombices, in particular that of the willow. In 

 eating, the concussion of their jaws or lips makes a peculiar 

 noise, which may be heard at some distance. 



Although the carps can remain a long time without taking 

 any nourishment, nevertheless, when they have food in abund- 

 ance they eat with so much gluttony as to produce fatal indi- 

 gestions. 



During winter they bury themselves in the mud, and pass 

 many months without eating, assembled in great numbers 

 side by side. But in spring, those which inhabit rivers and 

 streams hasten from their asylums to more tranquil waters, 

 and to places covered with plants. It then generally hap- 

 pens that many males follow a single female, and if in their 

 voyage any barrier should oppose itself to their progress, they 

 endeavour to cross it, and for that purpose sometimes raise 

 themselves to the height of six feet out of the water, by 

 placing themselves on their side, approximating the head 



