DIPNEUSTI 



5'3 



m.b. 



f. 



change in its surroundings the Fish hibernates, or passes into a 

 summer sleep, until the next rainy season brings about conditions 

 more favourable to active life. Preparatory to this summer sleep, 

 and before the ground becomes too hard, the Fish makes its way 

 into the mud to a depth of about 18 inches, and there coils 

 itself up in a flask-like en- 

 largement (Fig. 307) at the 

 bottom of the burrow, which 

 is lined by a capsule of 

 hardened mucus secreted by 

 the glands of the skin. 1 The 

 mouth of the flask is closed 

 by the capsular wall or lid, 

 which is perforated by a 

 small aperture. The margins 

 of this aperture are pushed 

 inwards, so as to form a 

 tubular funnel for insertion 

 between the lips of the Fish. 

 While encapsuled in its 

 cocoon the Fish is surrounded 

 by a soft slimy mucus, no 

 doubt for the purpose of 

 keeping the skin moist, and 

 its lungs are the sole breath- 

 ing organs, the air passing 

 from the open mouth of the 

 burrow through the hole in 



the lid directly to the mouth FlG - 307.-Diagram of a torpid Protopterus 'in 



17 situ, c, Cocoon ; e, earth ; /, fuimel leading 



of the animal. The nutri- to the month of the Fish ; /, lid ; m, mouth : 



tion Of the dormant Fish is A mouth of the burrow; t, tail. (From 



Newton Parker.) 



effected by the absorption of 



the fat stored up about the kidneys and gonads, somewhat after 



a fashion not unknown in the fat-bodies of Insects and the hiber- 



nating glands of Rodents. Even portions of the caudal muscles 

 undergo fatty degeneration, and thus, in a way which recalls the 

 mode of nutrition of the Salmon during the breeding season, and of 

 the Tadpole during its metamorphosis, a further store of nutritive 

 material becomes available for the sustenance of the Fish during 



1 Newton Parker, Trans. Roy. Irish Acad. xxx. 1892, p. 201. 

 VOL. VII 2 L 



