1868.] DR. F. DAY ON INDIAN FRESHWATER FISHES. 287 



mud ; and in Souiersetshire the people know how to find the holes 

 in which they are by the hoar frost not lying over them as it does 

 elsewhere, and dig them out in heaps*. Dr. Mitchell f also observes 

 that Eels in the winter lie concealed in the mud, and are taken in 

 great numbers by spearing them. Carps bury themselves in the 

 mud, and pass many months without eating, assembled in great 

 numbers side by side J. Yarrell§, quoting from a letter, says that 

 Soles frequent the river Arun nearly as high up as the town of Arun- 

 del, and remain in it the whole year, burying themselves in the 

 sand during the cold months. In the West Indies the genus 

 Callichthys is mentioned || as one of which the species are known to 

 bury themselves when the tanks dry up. The Callichthys asper is 

 also occasionally found when digging for wells IT- The Crocodile is 

 frequently dug up in a torpid state, in Ceylon, from the mud of 

 dried-up tanks during the hot months ; as food and water fail him 

 he gradually retires into the mud. Snails in the same manner glue 

 down their operculum, and descend into the nmd until released by 

 the rains, when they immediately deposit their ora. Why should 

 not freshwater fish in India sestivate in the same manner ? 



An Anabas was received by Sir Emerson Tennent from the 

 Moodliar of Matura, which was stated to have been dug out of a 

 dried-up tank, a foot and half below the surface of the earth, 

 ■where the mud was still moist, although the surface was dry and 

 hard. This gentleman also mentions that Mr. Whiting, the chief 

 civil officer in the western province, informed him that he had 

 accidentally been present twice when the villagers had been engaged 

 in digging up fish. The ground was firm and hard. " As the men 

 flung out lumps of it with a spade they fell to pieces, disclosing fish 

 from nine to twelve inches long, which were full-grown and healthy, 

 and jumped on the bank when exposed to the light"**. 



Another question which arises is, whether these fish do not sesti- 

 vate with the ova contained within them in a torpid state, ready to 

 be deposited as soon as the return of moisture arouses the vital 

 powers of the parent fishes. It is well known that the hatching of 

 ova can be retarded by the use of ice, why not also by aestivation 

 from the effects of heat 1 In support of this view I may mention 

 that in 1866, when on a march to Kurnool, I witnessed a heavy 

 shower of rain, the first which had occurred in those parts for 

 months, the country being quite dried up from want of water. A 

 few hours subsequently I observed a number of Ampullarice in an 

 open ditch full of water depositing their long stringy ova. They 

 must consequently have become torpid with the ova within them, and 

 immediately on their resuscitation they, being aroused into activity 

 by the occurrence of rain, commenced to increase their species. And 



* Yarrell's ' British Fishes,' vol. ii. p. 288. 



t "Fishes of New York," Transactions of the Literary and Philosophical 

 Society of New York. 



X Cuvier's ' Regne Animal.' § British Fishes, ii. \>. 258. 



II Cut. & Val. vol. xv. ^ Cuv. & Val. vol. xy. 



** Ceylon, vol. i. p. 220. 



