432 Fish and Drought 



of it in the short time that I was observing they must have been 

 packed very closely, and in such an orderly way that, with the 

 return of water in sufficient quantity, they were able to take 

 to it again apparently without having suffered at all. 



Although the instinct of the fish seems to have sufficed to 

 make them foresee and provide for the dryness, it does not 

 seem in all cases to have been sufficient to enable them to 

 judge correctly the moment for beginning their release. 



Of the different species which inhabit the waters of the 

 ditch, the carp and the tench have the habit of burying them- 

 selves in the mud every winter; but the perch and the pike 

 have not this habit ; both can be caught at any time in winter, 

 even under a covering of ice ; yet both the pike and the perch 

 must have buried themselves with quite as much skill as the 

 carp or the tench. 



But in a climate like that of this part of France shallow 

 lakes and ponds may suffer shortage of water by congelation 

 as well as by evaporation; and the Prince informed me that 

 he remembered one winter when in many places the water of 

 the ditch was frozen almost, if not quite, to the bottom, and 

 quantities of pike and perch were frozen into the ice. This 

 form of desiccation did not prompt them to seek refuge in 

 the mud. 



It is evident that if the summer of 1911 had marked the 

 beginning of a secular period of dryness, such that the canals 

 were not again to be flooded, the fish which took to the mud 

 in that summer would be kept there. They would die and 

 decay in situ, and would be perfectly preserved in well-arranged 

 though crowded masses. Eventually, if the change of climate 

 was final, they would form a rich and interesting bed of fossil 

 fishes. But the interest would depend not only on the abun- 

 dance of fossils in the muddy matrix of one part of the trough- 

 like formation; it would be intensified by their complete 

 absence in the hardened marly matrix of the other part. 



Before serious drying took place the ditch, or trough, was 

 covered by a continuous sheet of water in which the fish and 

 other creatures could circulate freely to all parts. So soon, 

 however, as actual desiccation appeared to be imminent, the 



