514 FISHES CHAP. 



its long summer nap. It is highly probable that the exceptionally- 

 numerous leucocytes act as carriers in the work of transporting 

 the fatty particles to the different organs and tissues of the body. 

 The length of the summer sleep naturally varies with the duration 

 of the dry season, and probably it lasts on an average nearly half 

 the year (August to December). The cocoons, imbedded in an 

 outward casing of hardened mud, have often been brought to Europe, 

 and when placed in water of suitable temperature the long torpid 

 Protopterus escapes from its prison in a perfectly healthy con- 

 dition, and resumes its partly branchial and partly pulmonary 

 mode of breathing. The negroes of the West Coast of Africa arc 

 very partial to these Fishes, which they dig out of the dried 

 marshes and preserve in their clumps of mud for food. With 

 the advent of the rainy season, when the marshes become flooded, 

 the Protopterus emerges from its cocoon, and returning to its 

 former active life, soon enters upon the task of reproducing its 

 kind. The important observations of Budgett 1 have thrown 

 much light on the curious breeding habits and development of 

 these Fishes. The Fish makes a nest near the edge of a swamp. 

 The nest is simply a hole of irregular shape, about a foot 

 in depth, filled with water and surrounded by long grass (Fig. 

 308). There is no lining to the nest, and the eggs are deposited 

 on the bare mud. Until the eggs are hatched, which occurs 

 about the eighth day, and while the larvae are in the nest, the 

 male remains on guard, and is apt to bite severely an incautious 

 intruder. Probably with the view of aerating the eggs the 

 water is continually lashed about by the tail of the guardian 

 parent. The male has no trace of the peculiar vascular filaments 

 which adorn the pelvic limbs of the male Lepidosiren during the 

 breeding season. The early developmental stages are similar in 

 their main outlines to those of Neoceratodus, but the young are 

 very different. When the young Protopterus (Fig. 309) is hatched 

 it is provided with a crescentic glandular sucker or cement-organ, 

 situated on the under side of the head behind the mouth, by 

 means of which the larva attaches itself to the sides of the nest, 

 or of the vessel in which it is confined, much in the same way as 

 the young Lepidosteus, and probably for the same reason. It 

 may be remarked that the sucker agrees in structure, position, 

 and function with that found in Amphibian tadpoles, but it 



1 Trans. Zool. Soc. xvi. Pt. ii. 1901, p. 119. 



